Code SQL statements in COBOL applications

This topic describes the unique application and coding requirements for embedding SQL statements in a COBOL program. Requirements for host structures and host variables are defined.

The iSeries™ system supports more than one COBOL compiler. The DB2^® UDB Query Manager and SQL Development Kit licensed program only supports the COBOL for iSeries and ILE COBOL for iSeries languages.

• Define the SQL communications area in COBOL applications that use SQL
  A COBOL program can be written to use the SQLCA to check return status for embedded SQL statements, or the program can use the SQL diagnostics area to check return status.
• Define SQL descriptor areas in COBOL applications that use SQL
  There are two types of SQL descriptor areas. One is defined with the ALLOCATE DESCRIPTOR statement. The other is defined using the SQLDA structure. In this topic, only the SQLDA form is discussed.
• Embed SQL statements in COBOL applications that use SQL
  SQL statements can be coded in COBOL program sections as in this table.
• Use host variables in COBOL applications that use SQL
  All host variables used in SQL statements must be explicitly declared prior to their first use.
• Use host structures in COBOL applications that use SQL
  A host structure is a named set of host variables that is defined in your program's DATA DIVISION.
• Use external file descriptions in COBOL applications that use SQL
  SQL uses the COPY DD-format-name, COPY DD-ALL-FORMATS, COPY DDS-format-name, COPY DDR-format-name, COPY DDR-ALL-FORMATS, COPY DDSR-format-name, COPY DDS-ALL-FORMATS, and COPY DDSR-ALL-FORMATS to retrieve host variables from the file definitions.
• Determine equivalent SQL and COBOL data types
  The precompiler determines the base SQLTYPE and SQLLEN of host variables based on this table. If a host variable appears with an indicator variable, the SQLTYPE is the base SQLTYPE plus one.
• Use indicator variables in COBOL applications that use SQL
  An indicator variable is a two-byte integer (PIC S9(m) USAGE BINARY, where m is from 1 to 4).