SQL/PSM

{{infobox programming language

| name = SQL/PSM

| logo =

| paradigm = Multi-paradigm

| year = 1996

| designer =

| developer =

| latest_release_version = SQL:2023

| latest_release_date =

| latest_preview_version =

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| turing-complete = Yes

| typing =

| implementations = PL/SQL
MySQL/MariaDB
IBM's SQL PL
Mimer SQL

| influenced_by = PL/SQL
Ada{{Citation | url = http://ocelot.ca/blog/blog/2015/01/15/stored-procedures-critiques-and-defences/ | title = Stored Procedures: critiques and defences | year = 2015 | first1 = Peter | last1 = Gulutzan }}

| influenced =

| operating_system = Cross-platform (multi-platform)

| license =

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}}

SQL/PSM (SQL/Persistent Stored Modules) is an ISO standard mainly defining an extension of SQL with a procedural language for use in stored procedures. Initially published in 1996 as an extension of SQL-92 (ISO/IEC 9075-4:1996, a version sometimes called PSM-96 or even SQL-92/PSM{{Cite journal | last1 = Eisenberg | first1 = A. | title = New standard for stored procedures in SQL | doi = 10.1145/245882.245907 | journal = ACM SIGMOD Record | volume = 25 | issue = 4 | pages = 81–88| year = 1996 | s2cid = 13023149 | doi-access = free }}), SQL/PSM was later incorporated into the multi-part SQL:1999 standard, and has been part 4 of that standard since then, most recently in SQL:2023.{{Citation | url = https://www.iso.org/standard/76585.html | contribution = SQL:2023 | title = Catalogue | publisher = ISO | format = webshop}} The SQL:1999 part 4 covered less than the original PSM-96 because the SQL statements for defining, managing, and invoking routines were actually incorporated into part 2 SQL/Foundation, leaving only the procedural language itself as SQL/PSM.{{cite book| first1 = Jim| last1 = Melton| first2 = Alan R| last2 = Simon| title = SQL: 1999| year = 2002| publisher = Morgan Kaufmann| isbn = 978-1-55860-456-8| pages = [https://archive.org/details/sql1999understan0000melt/page/541 541–42]| url-access = registration| url = https://archive.org/details/sql1999understan0000melt/page/541}} The SQL/PSM facilities are still optional as far as the SQL standard is concerned; most of them are grouped in Features P001-P008.

SQL/PSM standardizes syntax and semantics for control flow, exception handling (called "condition handling" in SQL/PSM), local variables, assignment of expressions to variables and parameters, and (procedural) use of cursors. It also defines an information schema (metadata) for stored procedures. SQL/PSM is one language in which methods for the SQL:1999 structured types can be defined. The other is Java, via SQL/JRT.

SQL/PSM is derived, seemingly directly, from Oracle's PL/SQL. Oracle developed PL/SQL and released it in 1991, basing the language on the US Department of Defense's Ada programming language. However, Oracle has maintained a distance from the standard in its documentation. IBM's SQL PL (used in DB2) and Mimer SQL's PSM{{Cite web|url=https://developer.mimer.com/article/stored-procedures-in-mimer-sql/|title = Stored Procedures in Mimer SQL}} were the first two products officially implementing SQL/PSM. It is commonly thought that these two languages, and perhaps also MySQL/MariaDB's procedural language, are closest to the SQL/PSM standard.

{{cite book | first1 = Guy | last1 = Harrison| first2 = Steven | last2 = Feuerstein|title=MySQL Stored Procedure Programming|url= https://books.google.com/books?id=YpeP0ok0cO4C&pg=PT75 | year=2008|publisher=O'Reilly |isbn = 978-0-596-10089-6 |page= 49}}

{{Cite web|url=https://mariadb.com/kb/en/library/stored-procedures/|title=Stored Procedures|website=MariaDB KnowledgeBase}} However, a PostgreSQL addon implements SQL/PSM{{Citation | url = https://github.com/okbob/plpsm0 | format = git | type = repository | title = plpsm0| date = 7 July 2020 }}.{{Citation | publisher = PostgreSQL | url = http://www.postgresql.org/message-id/1305291347.14548.13.camel@jara.office.nic.cz | date = May 2011 | title = Announce}}.{{Cite web|url=https://www.postgresql.org/message-id/CAFj8pRDWFdcjNSnwQB_3j1-rMO6b8=TmLTNBvDCSpRrOW2Dfeg@mail.gmail.com|title=PostgreSQL: Proposal: PL/pgPSM for 9.3|website=www.postgresql.org|date=22 February 2012}}{{Citation | title = SQL/PSM | format = wigl | url = http://postgres.cz/wiki/SQL/PSM_Manual | publisher = PostgreSQL | type = manual | year = 2008}}. (alongside its other procedural languages like the PL/SQL-derived plpgsql), although it is not part of the core product.{{Citation | contribution-url = http://www.postgresql.org/docs/9.2/static/features.html | publisher = PostgreSQL | title = Documentation | edition = 9.2 | contribution = SQL Conformance}}.

RDF functionality in OpenLink Virtuoso was developed entirely through SQL/PSM, combined with custom datatypes (e.g., ANY for handling URI and Literal relation objects), sophisticated indexing, and flexible physical storage choices (column-wise or row-wise).