SQL Language Elements

These topics provide detailed descriptions of the language elements and conventions of Sybase IQ SQL.

• Keywords
  Each SQL statement contains one or more keywords.
• Identifiers
  Identifiers are names of objects in the database, such as user IDs, tables, and columns.
• Strings
  Strings are either literal strings, or expressions with CHAR or VARCHAR data types.
• Expressions
  Expressions are formed from several different kinds of elements, such as constants, column names, SQL operators, and subqueries.
• Search Conditions
  Conditions are used to choose a subset of the rows from a table, or in a control statement such as an IF statement to determine control of flow.
• Special Values
  Special values can be used in expressions, and as column defaults when creating tables.
• Variables
  Sybase IQ supports local variables, connection-level variables, and global variables.
• Comments
  Use comments to attach explanatory text to SQL statements or statement blocks. The database server does not execute comments.
• NULL Value
  Use NULL to specify a value that is unknown, missing, or not applicable.