Archive for the ‘Windows 11’ Category
MySQL @SQL_MODE
Installing MySQL Workbench 8 on Windows, we discovered that the default configuration no longer sets ONLY_FULL_GROUP_BY as part of the default SQL_MODE parameter value. While I’ve written a stored function to set the SQL_MODE parameter value for a session, some students didn’t understand that such a call is only valid in the scope of a connection to the database server. They felt the function didn’t work because they didn’t understand the difference between connecting to the MySQL CLI and clicking the lightening bolt in MySQL Workbench.
So, here are the instructions to reset the default SQL_MODE parameter value for Windows. You need to edit the setting in the my.ini file, which is in the C:\ProgramData\MySQL\MySQL Server 8.0 directory. The default installation will have the following:
# Set the SQL mode to strict sql-mode="STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION" |
You need to change it to the following in an editor with Administrative privileges:
# Set the SQL mode to strict sql-mode="STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION,ONLY_FULL_GROUP_BY" |
Then, you need to connect to the services by launching services.msc from the command prompt. In the list of services find MYSQL80 service and restart it. You can verify it by connecting to the MySQL 8.0.* server and running the following SQL query:
SELECT @@SQL_MODE: |
That’s how you convert Windows to use only traditional group by behaviors in SQL. As always, I hope this helps those looking for a solution.
Oracle DSN Security
Oracle disallows entry of a password value when configuring the ODBC’s Windows Data Source Name (DSN) configurations. As you can see from the dialog’s options:
So, I check the Oracle ODBC’s property list with the following PowerShell command:
Get-Item -Path Registry::HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI\Oracle | Select-Object |
It returned:
Oracle Driver : C:\app\mclaughlinm\product\18.0.0\dbhomeXE\BIN\SQORA32.DLL
DisableRULEHint : T
Attributes : W
SQLTranslateErrors : F
LobPrefetchSize : 8192
AggregateSQLType : FLOAT
MaxTokenSize : 8192
FetchBufferSize : 64000
NumericSetting : NLS
ForceWCHAR : F
FailoverDelay : 10
FailoverRetryCount : 10
MetadataIdDefault : F
BindAsFLOAT : F
BindAsDATE : F
CloseCursor : F
EXECSchemaOpt :
EXECSyntax : F
Application Attributes : T
QueryTimeout : T
CacheBufferSize : 20
StatementCache : F
ResultSets : T
MaxLargeData : 0
UseOCIDescribeAny : F
Failover : T
Lobs : T
DisableMTS : T
DisableDPM : F
BatchAutocommitMode : IfAllSuccessful
Description : Oracle ODBC
ServerName : xe
Password :
UserID : c##student
DSN : Oracle |
Then, I used this PowerShell command to set the Password property:
Set-ItemProperty -Path Registry::HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI\Oracle -Name "Password" -Value 'student' |
After setting the Password property’s value, I queried it with the following PowerShell command:
Get-ItemProperty -Path Registry::HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI\Oracle | Select-Object -Property "Password" |
It returns:
Password : student |
After manually setting the Oracle ODBC DSN’s password value you can now connect without providing a password at runtime. It also means anybody who hacks the Windows environment can access the password through trivial PowerShell command.
I hope this alerts readers to a potential security risk when you use Oracle DSNs.
MySQL Windows DSN
Almost a Ripley’s Believe It or Not. An prior data science student told me that his new IT department setup a Windows component that let him connect his Excel Spreadsheets to their production MySQL database without a password. Intrigued, I asked if it was a MySQL Connector/ODBC Data Source Configuration, or DSN (Data Source Name)?
He wasn’t sure, so I asked him to connect to PowerShell and run the following command:
Get-Item -Path Registry::HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI\MySQL |
It returned something like this (substituting output from one of my test systems):
Hive: HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI
Name Property
---- --------
MySQL Driver : C:\Program Files\MySQL\Connector ODBC 8.0\myodbc8w.dll
DESCRIPTION : MySQL ODBC Connector
SERVER : localhost
UID : student
PWD : student
DATABASE : studentdb
PORT : 3306 |
The student was stunned and concerned he was compromising his employer’s system security. I suggested he share the information with his IT department so they could provide a different approach for his access to the production database. His IT department immediately agreed. Unfortunately, he’s bummed he can’t simply access the data through Excel.
I told him they were welcome to use the MySQL Connect Dialog PowerShell solution that I wrote. It creates a minimal MySQL DSN and requires a manual password entry through the PowerShell Dialog box. I also suggested that they look into the PowerShell Excel Module.
I also suggested they develop a query only copy of the production database, or shift access to a data warehouse. Needless to say, it wasn’t a large corporation.
As always, I hope this helps others.
What’s up on M1 Chip?
I’ve been trying to sort out what’s up on Oracle’s support of Apple’s M1 (arm64) chip. It really is a niche area. It only applies to those of us who work on a macOS machines with Oracle Database technology; and then only when we want to install a version of Oracle Database 21c or newer in Windows OS for testing. Since bootcamp is now gone, these are only virtualized solutions through a full virtualization product or containerized with Docker of Kubernetes.
The Best Virtual Machine Software for Mac 2022 (4/11/2022) article lets us know that only Parallels fully supports Windows virtualization on the ARM64 chip. Then, there’s the restriction that you must use Monterey or Big Sur (macOS) and Windows 11 arm64.
Instructions were published on On how to run Windows 11 on an Apple M1 a couple weeks ago. They use the free UTM App from the Apple Store and provide the download site for the Windows Insider Program. You can’t get a copy of Windows 11 arm64 without becoming part of the Windows Insider Program.
The next step would be to try and install Oracle Database 21c on Windows 11 arm64, which may or may not work. At least, I haven’t tested it yet and can’t make the promise that it works. After all, I doubt it will work because the Oracle Database 21c documentation says it only supports x64 (or Intel) architecture.
If anybody knows what Oracle has decided, will decide or even their current thinking on the issue, please make a comment.
MySQL RegExp Default
We had an interesting set of questions regarding the REGEXP comparison operator in MySQL today in both sections of Database Design and Development. They wanted to know the default behavior.
For example, we built a little movie table so that we didn’t change their default sakila example database. The movie table was like this:
CREATE TABLE movie ( movie_id int unsigned primary key auto_increment , movie_title varchar(60)) auto_increment=1001; |
Then, I inserted the following rows:
INSERT INTO movie ( movie_title ) VALUES ('The King and I') ,('I') ,('The I Inside') ,('I am Legend'); |
Querying all results with this query:
SELECT * FROM movie; |
It returns the following results:
+----------+----------------+ | movie_id | movie_title | +----------+----------------+ | 1001 | The King and I | | 1002 | I | | 1003 | The I Inside | | 1004 | I am Legend | +----------+----------------+ 4 rows in set (0.00 sec) |
The following REGEXP returns all the rows because it looks for a case insensitive “I” anywhere in the string.
SELECT movie_title FROM movie WHERE movie_title REGEXP 'I'; |
The implicit regular expression is actually:
WHERE movie_title REGEXP '^.*I.*$'; |
It looks for zero-to-many of any character before and after the “I“. You can get any string beginning with an “I” with the “^I“; and any string ending with an “I” with the “I$“. Interestingly, the “I.+$” should only match strings with one or more characters after the “I“, but it returns:
+----------------+ | movie_title | +----------------+ | The King and I | | The I Inside | | I am Legend | +----------------+ 3 rows in set (0.00 sec) |
This caught me by surprise because I was lazy. As pointed out in the comment, it only appears to substitute a “.*“, or zero-to-many evaluation for the “.+” because it’s a case-insensitive search. There’s another lowercase “i” in the “The King and I” and that means the regular expression returns true because that “i” has one-or-more following characters. If we convert it to a case-sensitive comparison with the keyword binary, it works as expected because it ignores the lowercase “i“.
WHERE binary movie_title REGEXP '^.*I.*$'; |
This builds on my 10-year old post on Regular Expressions. As always, I hope these notes helps others discovering features and behaviors of the MySQL database, and Bill thanks for catching my error.
Record Type Arrays
Another question that I was asked today: “Can you create an array of a record type in PL/pgSQL?” The answer is yes.
You first have to create a type, which is what you do when you want to create a table with an embedded table. This is a simple full_name record type:
CREATE TYPE full_name AS ( first_name VARCHAR(20) , middle_name VARCHAR(20) , last_name VARCHAR(20)); |
The following DO block shows you how to create a record type array and then print it’s contents in a FOR-LOOP:
DO $$ DECLARE -- An array of full_name records. list full_name[] = array[('Harry','James','Potter') ,('Ginevra','Molly','Potter') ,('James','Sirius','Potter') ,('Albus','Severus','Potter') ,('Lily','Luna','Potter')]; BEGIN -- Loop through the integers. FOR i IN 1..CARDINALITY(list) LOOP RAISE NOTICE '%, % %', list[i].last_name, list[i].first_name, list[i].middle_name; END LOOP; END; $$; |
Since you typically only have a single dimension array with record-type structure, using CARDINALITY is clearer than ARRAY_LENGTH(list,1). If you don’t agree use the latter.
It prints the following:
NOTICE: Potter, Harry James
NOTICE: Potter, Ginevra Molly
NOTICE: Potter, James Sirius
NOTICE: Potter, Albus Severus
NOTICE: Potter, Lily Luna
DO |
As always, I hope this helps those looking for a solution to this type of problem.
Multidimension Arrays
Picking up where I left off on yesterday’s post on PostgreSQL arrays, you can also write multidimensional arrays provided all the nested arrays are equal in size. You can’t use the CARDINALITY function to determine the length of nested arrays, you must use the ARRAY_LENGTH to determine the length of subordinate arrays.
Here’s an example file with a multidimensional array of integers:
DO $$ DECLARE /* Declare an array of integers with a subordinate array of integers. */ list int[][] = array[array[1,2,3,4] ,array[1,2,3,4] ,array[1,2,3,4] ,array[1,2,3,4] ,array[1,2,3,4]]; row varchar(20) = ''; BEGIN /* Loop through the first dimension of integers. */ <<Outer>> FOR i IN 1..ARRAY_LENGTH(list,1) LOOP row = ''; /* Loop through the second dimension of integers. */ <<Inner>> FOR j IN 1..ARRAY_LENGTH(list,2) LOOP IF LENGTH(row) = 0 THEN row = row || list[i][j]; ELSE row = row || ',' || list[i][j]; END IF; END LOOP; /* Exit outer loop. */ RAISE NOTICE 'Row [%][%]', i, row; END LOOP; END; $$; |
It prints:
NOTICE: Row [1][1,2,3,4] NOTICE: Row [2][1,2,3,4] NOTICE: Row [3][1,2,3,4] NOTICE: Row [4][1,2,3,4] NOTICE: Row [5][1,2,3,4] DO |
Multidimensional arrays are unique to PostgreSQL but you can have nested lists of tables or varrays inside an Oracle database. Oracle also supports nested lists that are asynchronous.
As always, I hope this helps those trying sort out the syntax.
Parameter Validation
I was trying to explain how to validate PowerShell script parameters to my students when I found the number and quality of enum data type examples was woefully inadequate. Here’s a series of examples that show you how to validate input parameters against an enum list of values.
The basic concept requires you to validate an element in an enum type. It uses a literal value
1 2 3 4 5 6 7 8 9 10 | # Create a enum type. Add-Type -TypeDefinition @" public enum msgTypes { moe, larry, curly } "@ # Check whether the value is found in the enum type. if ([enum]::isDefined(([msgTypes]), [msgTypes]::moe)) { Write-Host "Success" } |
You test this testEnum1.ps1 script file with this syntax:
powershell testEnum1.ps1 |
It prints:
Success |
The next sample embeds the validation in a local function:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | # Create a enum type. Add-Type -TypeDefinition @" public enum msgTypes { moe, larry, curly } "@ # A local function for verbose reporting. function Print-Message ($msg) { # Check whether the value is found in the enum type. if ([enum]::isDefined(([msgTypes]), [msgTypes]::$msg)) { Write-Host "Success" } } # Call the function with a literal value. Print-Message "moe" |
You test this testEnum2.ps1 script file with this syntax:
powershell testEnum2.ps1 |
It also prints:
Success |
The next sample testEnum3.ps1 accepts a parameter and passes it to the validation function:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | # Create a enum type. Add-Type -TypeDefinition @" public enum msgTypes { moe, larry, curly } "@ # A local function for verbose reporting. function Print-Message ($msg) { # Check whether the value is found in the enum type. if ([enum]::isDefined(([msgTypes]), [msgTypes]::$msg)) { Write-Host "Success" } } # Wrap the Parameter call to avoid a type casting warning. try { param ( [Parameter(Mandatory)][hashtable]$args ) } catch {} # Call the function with a literal value. Print-Message "moe" |
You test this testEnum.ps1 script file with this syntax:
powershell testEnum3.ps1 moe |
It also prints:
Success |
However, if you don’t pass a parameter to the testEnum3.ps1, like this
powershell testEnum3.ps1 |
It raises the following error:
Exception calling "IsDefined" with "2" argument(s): "Value cannot be null. Parameter name: value" At C:\Data\cit225\mysql\test\testEnum3.ps1:9 char:7 + if ([enum]::isDefined(([msgTypes]), [msgTypes]::$msg)) { + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : NotSpecified: (:) [], MethodInvocationException + FullyQualifiedErrorId : ArgumentNullException |
Rewriting the Print-Message function in the script may appear to fix the problem. At least, a missing parameter won’t cause an error when you wrap the call to the isDefined method inside an if-statement.
Here’s how that wrapping attempt would look:
7 8 9 10 11 12 13 14 15 16 | # A local function for verbose reporting. function Print-Message ($msg) { if (!($msg -eq $null)) { if ([enum]::isDefined(([msgTypes]), [msgTypes]::$msg)) { Write-Host "Success" } } else { Write-Host "Failure" } } |
While the prior change to the Print-Message function manages the lack of a parameter, it doesn’t prevent a failure when you pass an incorrect parameter. A new variation of the old error occurs when you pass a parameter that is not a member of the enum type, like
powershell testEnum4.ps1 Shem |
It now prints:
Failure |
So, you need to complete another step. Our woeful tale of parameter validation against a set of possible enum values isn’t quite complete. That’s because any incorrect parameter value raises a null value when isDefined method can’t find a valid value in the enum type. This standard behavior means that the isDefined method returns this error message:
Exception calling "IsDefined" with "2" argument(s): "Value cannot be null. Parameter name: value" At C:\Data\cit225\mysql\test\testEnum4.ps1:10 char:9 + if ([enum]::isDefined(([msgTypes]), [msgTypes]::$msg)) { + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : NotSpecified: (:) [], MethodInvocationException + FullyQualifiedErrorId : ArgumentNullException |
After all the effort to sort through how PowerShell handles the isDefined method and navigating Microsoft’s limited PowerShell examples, we’ve travelled down a rabbit hole. The problem is that the isDefined method isn’t terribly useful.
You need to use another getValues method, which returns the set of member values from the enum type. This requires you to write a new function. Find-EnumMatch seems an appropriate Pascal-like name for that function because that’s what it will do. Writing the new function also simplifies the Print-Message function.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 | # Create a enum type for statements, for future use. Add-Type -TypeDefinition @" public enum msgTypes { moe, larry, curly } "@ # A local function to find a valid enum member. function Find-EnumMatch ($typeof, $member) { # Set default return value. $evaluated = $false # Check for a not null match to an enum member. if (!($msg -eq $null)) { foreach ($msgValue in $msgTypes = [enum]::getValues(([enum]::'[' + $typeof + ']'))) { if ($msgValue -eq $member) { $evaluated = $true break } } } # Return whether true or false. return $evaluated } # A local function for verbose reporting. function Print-Message ($msg) { # Check for a not null match to an enum member. if (find-enumMatch $msg) { Write-Host "Success" } else { Write-Host "Failure" } } # Wrap the Parameter call to avoid a type casting warning. try { param ( [Parameter(Mandatory)][hashtable]$args ) } catch {} |
Now, if we test the program with a valid, invalid, or null value parameter it works as expected. It prints “Success” when the parameter is found as a member of the enum type, and prints “Failure” when the parameter is null or not found as a member of the enum type. It also never raises an unhandled exception.
There’s an important explicit casting trick required on line #14 to avoid the following error:
Cannot convert argument "enumType", with value: "[msgTypes]", for "GetValues" to type "System.Type": "Cannot convert the "[msgTypes]" value of type "System.String" to type "System.Type"." At C:\Data\cit225\mysql\test\testEnum7.ps1:14 char:27 + ... ($msgValue in $msgTypes = [enum]::getValues(('[' + $typeof + ']'))) { + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : NotSpecified: (:) [], MethodException + FullyQualifiedErrorId : MethodArgumentConversionInvalidCastArgument |
While many developers might think that you can write the line without explicitly casting the enum name enclosed by square brackets, you actually have to explicitly cast it.
As always, I hope this helps those looking for an arcane bit of knowledge. While handling parameters is routine, it sure appears the method for doing so in PowerShell with an enum type isn’t quite well documented.
PostgreSQL Install-Windows
A number of folks have asked me to create a post of a PostgreSQL installation on Windows. So, here is my step-by-step PostgreSQL 9.3 installation, and you can go further and learn how to setup your own PostgreSQL database schema.
Download PostgreSQL Database
You can start the download of PostgreSQL from this site. It leads you to the EnterpriseDB site, where you can download the prepackaged software.
Install PostgreSQL 9.3 on Windows
These steps walk you through installing PostgreSQL and the the pgJDBC v9.3, psqlODBC (32 bit), and psqlODBC (64 bit) packages.
- The first thing you need to do is launch the PostgreSQL file from download folder.
- After launching the downloaded file, you see an Open File – Security Warning dialog message. Click the Run button to run the PostgreSQL executable file.
- The first dialog screen is the Setup – PostgreSQL dialog, which welcomes you and prompts you to start the installtion of PostgreSQL. Click the Next button to continue.
- The Installation Directory dialog sets the location for the PostgreSQL server. Click the Next button to continue.
- The Data Directory dialog sets the location for the PostgreSQL server’s data repository. Click the Next button to continue.
- The first Setup dialog sets the database’s superuser password. Click the Next button to continue.
- The second Setup dialog sets the database’s listener port, which is Port
5432by default. Click the Next button to continue.
- The third Setup dialog sets the database’s default Locale. Click the Next button to continue.
- The Ready to Install dialog lets you start the installation. Click the Next button to continue.
- The Installing dialog lets you montor the unpacking of programs for the installation. You need not click any buttons to continue.
- The Completing the PostgreSQL Setup Wizard dialog advises you that you’ve completed the setup. Checking the Stack Builder check box lets you download and install additional tools, drivers, and applications. Click the Next button to continue.
- This is Welcome dialog to the Stack Builder. Click the Next button to continue.
- This is dialog lets you select applications that you would like to install. Click the plus symbol for the Database Drivers option to continue.
- In the modified dialog, click the pgJDBC v9.3, psqlODBC (32 bit), and psqlODBC (64 bit) check boxes. Then, click the Next button to continue.
- This dialog tells you the pgJDBC v9.3, psqlODBC (32 bit), and psqlODBC (64 bit) installed packages. Click the Next button to continue.
- This dialog lays a downloading progress bar while loading the additional packages. You don’t need to do anything to continue.
- This dialog lays a downloading progress bar while loading the additional packages. Click the Next button to continue.
- The Setup pgJDBC dialog welcomes you to the setup wizard. Click the Next button to continue.
- The Installation Directory dialog lets you set the pgJDBC installation directory. Click the Next button to continue.
- The Ready to Install dialog lets you install the pgJDBC package. Click the Next button to install it.
- The Setup dialog confirms you’ve installed the add-on packages. Click the Finish button to complete the installation.
Configure psqlODBC on Windows
These steps walk you through configuring the psqlODBC packages.
- The Setup dialog helps you configure the psqlODBC package. Click the Next button to install it.
- The Installation Directory dialog lets you set the psqlODBC installation directory. Click the Next button to continue.
- The Ready to Install dialog lets you install the psqlODBC package. Click the Next button to install it.
- The Ready to Install dialog lets you install the psqlODBC package. Click the Next button to install it.
- The Installing psqlODBC dialog displays a dialog while installing the psqlODBC package(s). You need not click anything, the dialog dismisses itself when complete.
- The Installing psqlODBC dialog displays a dialog while installing the psqlODBC package(s). You need not click anything, the dialog dismisses itself when complete.
- The Stack Builder dialog displays a message that everything is installed. Click the Finish button when complete.
Connect to the Default PostgreSQL database
You have two options for connecting to the PostgreSQL database. One uses the GUI pgAdmin III console and the other uses the command line.
Connect through pgAdmin III to the PostgreSQL Database
- In Windows, navigate to through the Start to the pgAdmin III menu option.
- After launching pgAdmin III, you’ll see the pgAdmin II console, displayed at left.
- Right click on the PostgreSQL 9.3 (localhost:5432) item in the Object browser and click the Connect menu choice from the floating menu.
- Enter the password you chose when installing the PostgreSQL Server, and click the OK button.
Connect through the Command-line to the PostgreSQL Database
These steps show you how to connect through the PostgreSQL Command Line Interface (CLI) – psql. psql is like Oracle’s sqlplus, MySQL’s mysql, and Microsoft SQL Server’s sqlcmd CLI interfaces. By default, the PostgreSQL binary directory is not in your default %PATH% environment variable, so you need to add it. I recommend an environment file because in a test situation you may not want to use it all the time.
Create the following directory for the environment file:
C:\Data\PostgreSQL\env |
You can create an environment file with any text editor or do it at the command line, like this:
COPY CON postgresqlenv.bat SET PATH=%PATH%;C:\Program Files\PostgreSQL\9.3\bin;. ^Z |
Then, you can source the environment file like this:
C:\> postgresql.bat |
Now, you can connect to the default database provided you understand that PostgreSQL Stack Builder set some values that differ from the defaults if you installed it manually. Specifically, they set the default value of the database to postgres and default value of the user to postgres.
That means you can connect with the following, provided you remember the password you used during installation:
C:\> psql -d postgres -U postgres |
You should see the following when you connect:
C:\> psql -d postgres -U postgres Password for user postgres: psql (9.3.3) WARNING: Console code page (437) differs from Windows code page (1252) 8-bit characters might not work correctly. See psql reference page "Notes for Windows users" for details. Type "help" for help. |
You can now submit interactive SQL statements or run batch files, like:
postgres=# SELECT 'Hello World!'; |
It displays:
?COLUMN? -------------- Hello World! (1 ROW) |
Adding a column alias to the string literal gives a more readable formatted output:
postgres=# SELECT 'Hello World!' AS "String Literal"; |
It displays:
String Literal ---------------- Hello World! (1 ROW) |
PostgreSQL’s CLI Help
You have the ability to do a lot with the PostgreSQL psql CLI. The general command to discover help is help, and it displays the following:
postgres=# help You are USING psql, the command-line interface TO PostgreSQL. TYPE: \copyright FOR distribution terms \h FOR help WITH SQL commands \? FOR help WITH psql commands \g OR terminate WITH semicolon TO EXECUTE query \q TO quit |
You quit PostgreSQL with a \q command:
postgres=# \q |
You can find more help with the \HELP or the \? commands:
\HELP |
It displays the following:
Available help: ABORT CLUSTER DEALLOCATE END ALTER AGGREGATE COMMENT DECLARE EXECUTE ALTER COLLATION COMMIT DELETE EXPLAIN ALTER CONVERSION COMMIT PREPARED DISCARD FETCH ALTER DATABASE COPY DO GRANT ALTER DEFAULT PRIVILEGES CREATE AGGREGATE DROP AGGREGATE INSERT ALTER DOMAIN CREATE CAST DROP CAST LISTEN ALTER EVENT TRIGGER CREATE COLLATION DROP COLLATION LOAD ALTER EXTENSION CREATE CONVERSION DROP CONVERSION LOCK ALTER FOREIGN DATA WRAPPER CREATE DATABASE DROP DATABASE MOVE ALTER FOREIGN TABLE CREATE DOMAIN DROP DOMAIN NOTIFY ALTER FUNCTION CREATE EVENT TRIGGER DROP EVENT TRIGGER PREPARE ALTER GROUP CREATE EXTENSION DROP EXTENSION PREPARE TRANSACTION ALTER INDEX CREATE FOREIGN DATA WRAPPER DROP FOREIGN DATA WRAPPER REASSIGN OWNED ALTER LANGUAGE CREATE FOREIGN TABLE DROP FOREIGN TABLE REFRESH MATERIALIZED VIEW ALTER LARGE OBJECT CREATE FUNCTION DROP FUNCTION REINDEX ALTER MATERIALIZED VIEW CREATE GROUP DROP GROUP RELEASE SAVEPOINT ALTER OPERATOR CREATE INDEX DROP INDEX RESET ALTER OPERATOR CLASS CREATE LANGUAGE DROP LANGUAGE REVOKE ALTER OPERATOR FAMILY CREATE MATERIALIZED VIEW DROP MATERIALIZED VIEW ROLLBACK ALTER ROLE CREATE OPERATOR DROP OPERATOR ROLLBACK PREPARED ALTER RULE CREATE OPERATOR CLASS DROP OPERATOR CLASS ROLLBACK TO SAVEPOINT ALTER OPERATOR CREATE INDEX DROP INDEX RESET ALTER OPERATOR CLASS CREATE LANGUAGE DROP LANGUAGE REVOKE ALTER OPERATOR FAMILY CREATE MATERIALIZED VIEW DROP MATERIALIZED VIEW ROLLBACK ALTER ROLE CREATE OPERATOR DROP OPERATOR ROLLBACK PREPARED ALTER RULE CREATE OPERATOR CLASS DROP OPERATOR CLASS ROLLBACK TO SAVEPOINT ALTER SCHEMA CREATE OPERATOR FAMILY DROP OPERATOR FAMILY SAVEPOINT ALTER SEQUENCE CREATE ROLE DROP OWNED SECURITY LABEL ALTER SERVER CREATE RULE DROP ROLE SELECT ALTER TABLE CREATE SCHEMA DROP RULE SELECT INTO ALTER TABLESPACE CREATE SEQUENCE DROP SCHEMA SET ALTER TEXT SEARCH CONFIGURATION CREATE SERVER DROP SEQUENCE SET CONSTRAINTS ALTER TEXT SEARCH DICTIONARY CREATE TABLE DROP SERVER SET ROLE ALTER TEXT SEARCH PARSER CREATE TABLE AS DROP TABLE SET SESSION AUTHORIZATION ALTER TEXT SEARCH TEMPLATE CREATE TABLESPACE DROP TABLESPACE SET TRANSACTION ALTER TRIGGER CREATE TEXT SEARCH CONFIGURATION DROP TEXT SEARCH CONFIGURATION SHOW ALTER TYPE CREATE TEXT SEARCH DICTIONARY DROP TEXT SEARCH DICTIONARY START TRANSACTION ALTER USER CREATE TEXT SEARCH PARSER DROP TEXT SEARCH PARSER TABLE ALTER USER MAPPING CREATE TEXT SEARCH TEMPLATE DROP TEXT SEARCH TEMPLATE TRUNCATE ALTER VIEW CREATE TRIGGER DROP TRIGGER UNLISTEN ANALYZE CREATE TYPE DROP TYPE UPDATE BEGIN CREATE USER DROP USER VACUUM CHECKPOINT CREATE USER MAPPING DROP USER MAPPING VALUES CLOSE CREATE VIEW DROP VIEW WITH |
You can find more help with the \HELP or the \? commands:
\? |
It displays the following:
General
\copyright show PostgreSQL usage and distribution terms
\g [FILE] or ; execute query (and send results to file or |pipe)
\gset [PREFIX] execute query and store results in psql variables
\h [NAME] help on syntax of SQL commands, * for all commands
\q quit psql
\watch [SEC] execute query every SEC seconds
Query Buffer
\e [FILE] [LINE] edit the query buffer (or file) with external editor
\ef [FUNCNAME [LINE]] edit function definition with external editor
\p show the contents of the query buffer
\r reset (clear) the query buffer
\s [FILE] display history or save it to file
\w FILE write query buffer to file
Input/Output
\copy ... perform SQL COPY with data stream to the client host
\echo [STRING] write string to standard output
\i FILE execute commands from file
\ir FILE as \i, but relative to location of current script
\o [FILE] send all query results to file or |pipe
\qecho [STRING] write string to query output stream (see \o)
Informational
(options: S = show system objects, + = additional detail)
\d[S+] list tables, views, and sequences
\d[S+] NAME describe table, view, sequence, or index
\da[S] [PATTERN] list aggregates
\db[+] [PATTERN] list tablespaces
\dc[S+] [PATTERN] list conversions
\dC[+] [PATTERN] list casts
\dd[S] [PATTERN] show object descriptions not displayed elsewhere
\ddp [PATTERN] list default privileges
\dD[S+] [PATTERN] list domains
\det[+] [PATTERN] list foreign tables
\des[+] [PATTERN] list foreign servers
\deu[+] [PATTERN] list user mappings
\dew[+] [PATTERN] list foreign-data wrappers
\df[antw][S+] [PATRN] list [only agg/normal/trigger/window] functions
\dF[+] [PATTERN] list text search configurations
\dFd[+] [PATTERN] list text search dictionaries
\dFp[+] [PATTERN] list text search parsers
\dFt[+] [PATTERN] list text search templates
\dg[+] [PATTERN] list roles
\di[S+] [PATTERN] list indexes
\dl list large objects, same as \lo_list
\dL[S+] [PATTERN] list procedural languages
\dm[S+] [PATTERN] list materialized views
\dn[S+] [PATTERN] list schemas
\do[S] [PATTERN] list operators
\dO[S+] [PATTERN] list collations
\dp [PATTERN] list table, view, and sequence access privileges
\drds [PATRN1 [PATRN2]] list per-database role settings
\ds[S+] [PATTERN] list sequences
\dt[S+] [PATTERN] list tables
\dT[S+] [PATTERN] list data types
\du[+] [PATTERN] list roles
\dv[S+] [PATTERN] list views
\dE[S+] [PATTERN] list foreign tables
\dx[+] [PATTERN] list extensions
\dy [PATTERN] list event triggers
\l[+] [PATTERN] list databases
\sf[+] FUNCNAME show a function's definition
\z [PATTERN] same as \dp
Formatting
\a toggle between unaligned and aligned output mode
\C [STRING] set table title, or unset if none
\f [STRING] show or set field separator for unaligned query output
\H toggle HTML output mode (currently off)
\pset NAME [VALUE] set table output option
(NAME := {format|border|expanded|fieldsep|fieldsep_zero|footer|null|
numericlocale|recordsep|recordsep_zero|tuples_only|title|tableattr|pager})
\t [on|off] show only rows (currently off)
\T [STRING] set HTML <table> tag attributes, or unset if none
\x [on|off|auto] toggle expanded output (currently off)
Connection
\c[onnect] {[DBNAME|- USER|- HOST|- PORT|-] | conninfo}
connect to new database (currently "studentdb")
\encoding [ENCODING] show or set client encoding
\password [USERNAME] securely change the password for a user
\conninfo display information about current connection
Operating System
\cd [DIR] change the current working directory
\setenv NAME [VALUE] set or unset environment variable
\timing [on|off] toggle timing of commands (currently off)
\! [COMMAND] execute command in shell or start interactive shell
Variables
\prompt [TEXT] NAME prompt user to set internal variable
\set [NAME [VALUE]] set internal variable, or list all if no parameters
\unset NAME unset (delete) internal variable
Large Objects
\lo_export LOBOID FILE
\lo_import FILE [COMMENT]
\lo_list
\lo_unlink LOBOID large object operations |
Have fun exploring PostgreSQL. You can click here to learn how to setup your own tablespace, database, and user. As always, I hope this helps those looking to discover how to install and use PostgreSQL.
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