Coding SQL statements in COBOL applications

There are unique application and coding requirements for embedding SQL statements in a COBOL program. In this topic, requirements for host structures and host variables are defined.

The System i® products support more than one COBOL compiler. The IBM® DB2® Query Manager and SQL Development Kit for i licensed program only supports the OPM COBOL and ILE COBOL programming languages.

Note: By using the code examples, you agree to the terms of the Code license and disclaimer information.

Defining the SQL communication area in COBOL applications that use SQL
A COBOL program can be written to use the SQL communication area (SQLCA) to check return status for embedded SQL statements, or the program can use the SQL diagnostics area to check return status.
Defining SQL descriptor areas in COBOL applications that use SQL
There are two types of SQL descriptor areas (SQLDAs). 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.
Embedding SQL statements in COBOL applications that use SQL
SQL statements can be coded in COBOL program sections as in this table.
Using host variables in COBOL applications that use SQL
All host variables used in SQL statements must be explicitly declared prior to their first use.
Using 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.
Using 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.
Determining 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.
Using 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).

Parent topic: Embedded SQL programming

Related concepts:

Writing applications that use SQL

Related reference:

Example programs: Using DB2 for i statements

Example: SQL statements in COBOL and ILE COBOL programs