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Syntax
Syntax
DESCRIBE
ESQL elements and statements
Writes information about a prepared statement to the SQL Descriptor Area (SQLDA). You use
a DESCRIBE statement in a series of steps that allows a program to accept SQL statements at run
time. Dynamically generated statements are not part of a program's source code; they are
generated at run time.
There are two forms of the DESCRIBE statement:
• The DESCRIBE BIND VARIABLES statement writes information about input variables in an
expression to an SQLDA. These variables can be substitution variable names or parameter
markers.
• The DESCRIBE SELECT LIST statement writes information about select list items in a
prepared SELECT statement to an SQLDA.
DESCRIBE [ BIND VARIABLES | SELECT LIST ] FOR statement_name
INTO input_sqlda_name ;
The SQLDA is a host language data structure used in dynamic SQL processing. DESCRIBE
statements write information about the number, data types, and sizes of input variables or select
list items to SQLDA structures. Program logic then processes that information to allocate
storage. OPEN, EXECUTE, and FETCH statements read the SQLDA structures for the addresses of
the allocated storage.
DESCRIBE BIND VARIABLES
Writes information about any input variables in the prepared statement to an input SQLDA
structure.
DESCRIBE BIND VARIABLES FOR statement_name INTO input_sqlda_name ;
statement_name
The name of an input SQL statement to be processed using dynamic SQL steps. Typically,
this is the same statement_name used in the PREPARE statement.
input_sqlda_name
The name of the SQLDA structure to which DESCRIBE will write information about input
variables. Input variables represent values supplied to INSERT and UPDATE statements at
run time, and to predicates in DELETE, UPDATE, and SELECT statements at run time.
To utilize the DESCRIBE BIND VARIABLES statement in your application, issue statements in the
following order:
1. PREPARE
2. DESCRIBE BIND VARIABLES
3. EXECUTE or OPEN CURSOR
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