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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >SQL Syntax</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REV="MADE" HREF="mailto:pgsql-docs@postgresql.org"><LINK REL="HOME" TITLE="PostgreSQL 9.2.24 Documentation" HREF="index.html"><LINK REL="UP" TITLE="The SQL Language" HREF="sql.html"><LINK REL="PREVIOUS" TITLE="The SQL Language" HREF="sql.html"><LINK REL="NEXT" TITLE="Lexical Structure" HREF="sql-syntax-lexical.html"><LINK REL="STYLESHEET" TYPE="text/css" HREF="stylesheet.css"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"><META NAME="creation" CONTENT="2017-11-06T22:43:11"></HEAD ><BODY CLASS="CHAPTER" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="5" ALIGN="center" VALIGN="bottom" ><A HREF="index.html" >PostgreSQL 9.2.24 Documentation</A ></TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A TITLE="The SQL Language" HREF="sql.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="sql.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="60%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="20%" ALIGN="right" VALIGN="top" ><A TITLE="Lexical Structure" HREF="sql-syntax-lexical.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="CHAPTER" ><H1 ><A NAME="SQL-SYNTAX" ></A >Chapter 4. SQL Syntax</H1 ><DIV CLASS="TOC" ><DL ><DT ><B >Table of Contents</B ></DT ><DT >4.1. <A HREF="sql-syntax-lexical.html" >Lexical Structure</A ></DT ><DD ><DL ><DT >4.1.1. <A HREF="sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS" >Identifiers and Key Words</A ></DT ><DT >4.1.2. <A HREF="sql-syntax-lexical.html#SQL-SYNTAX-CONSTANTS" >Constants</A ></DT ><DT >4.1.3. <A HREF="sql-syntax-lexical.html#SQL-SYNTAX-OPERATORS" >Operators</A ></DT ><DT >4.1.4. <A HREF="sql-syntax-lexical.html#SQL-SYNTAX-SPECIAL-CHARS" >Special Characters</A ></DT ><DT >4.1.5. <A HREF="sql-syntax-lexical.html#SQL-SYNTAX-COMMENTS" >Comments</A ></DT ><DT >4.1.6. <A HREF="sql-syntax-lexical.html#SQL-PRECEDENCE" >Operator Precedence</A ></DT ></DL ></DD ><DT >4.2. <A HREF="sql-expressions.html" >Value Expressions</A ></DT ><DD ><DL ><DT >4.2.1. <A HREF="sql-expressions.html#SQL-EXPRESSIONS-COLUMN-REFS" >Column References</A ></DT ><DT >4.2.2. <A HREF="sql-expressions.html#SQL-EXPRESSIONS-PARAMETERS-POSITIONAL" >Positional Parameters</A ></DT ><DT >4.2.3. <A HREF="sql-expressions.html#SQL-EXPRESSIONS-SUBSCRIPTS" >Subscripts</A ></DT ><DT >4.2.4. <A HREF="sql-expressions.html#FIELD-SELECTION" >Field Selection</A ></DT ><DT >4.2.5. <A HREF="sql-expressions.html#SQL-EXPRESSIONS-OPERATOR-CALLS" >Operator Invocations</A ></DT ><DT >4.2.6. <A HREF="sql-expressions.html#SQL-EXPRESSIONS-FUNCTION-CALLS" >Function Calls</A ></DT ><DT >4.2.7. <A HREF="sql-expressions.html#SYNTAX-AGGREGATES" >Aggregate Expressions</A ></DT ><DT >4.2.8. <A HREF="sql-expressions.html#SYNTAX-WINDOW-FUNCTIONS" >Window Function Calls</A ></DT ><DT >4.2.9. <A HREF="sql-expressions.html#SQL-SYNTAX-TYPE-CASTS" >Type Casts</A ></DT ><DT >4.2.10. <A HREF="sql-expressions.html#SQL-SYNTAX-COLLATE-EXPRS" >Collation Expressions</A ></DT ><DT >4.2.11. <A HREF="sql-expressions.html#SQL-SYNTAX-SCALAR-SUBQUERIES" >Scalar Subqueries</A ></DT ><DT >4.2.12. <A HREF="sql-expressions.html#SQL-SYNTAX-ARRAY-CONSTRUCTORS" >Array Constructors</A ></DT ><DT >4.2.13. <A HREF="sql-expressions.html#SQL-SYNTAX-ROW-CONSTRUCTORS" >Row Constructors</A ></DT ><DT >4.2.14. <A HREF="sql-expressions.html#SYNTAX-EXPRESS-EVAL" >Expression Evaluation Rules</A ></DT ></DL ></DD ><DT >4.3. <A HREF="sql-syntax-calling-funcs.html" >Calling Functions</A ></DT ><DD ><DL ><DT >4.3.1. <A HREF="sql-syntax-calling-funcs.html#SQL-SYNTAX-CALLING-FUNCS-POSITIONAL" >Using Positional Notation</A ></DT ><DT >4.3.2. <A HREF="sql-syntax-calling-funcs.html#SQL-SYNTAX-CALLING-FUNCS-NAMED" >Using Named Notation</A ></DT ><DT >4.3.3. <A HREF="sql-syntax-calling-funcs.html#SQL-SYNTAX-CALLING-FUNCS-MIXED" >Using Mixed Notation</A ></DT ></DL ></DD ></DL ></DIV ><P > This chapter describes the syntax of SQL. It forms the foundation for understanding the following chapters which will go into detail about how SQL commands are applied to define and modify data. </P ><P > We also advise users who are already familiar with SQL to read this chapter carefully because it contains several rules and concepts that are implemented inconsistently among SQL databases or that are specific to <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN >. </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sql.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sql-syntax-lexical.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >The SQL Language</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="sql.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Lexical Structure</TD ></TR ></TABLE ></DIV ></BODY ></HTML >