Call Level Interface Guide and Reference

Handling Stored Procedure Arguments (SQLDA)

Although stored procedures are, in most ways, like any other application, stored procedures written in CLI (and embedded SQL) must give special consideration to the SQLDA structure which contains the stored procedure arguments. The SQLDA structure is described in detail in the SQL Reference.

It is important to understand that all data stored in the SQLDA structure is stored as an SQL data type, and must be treated as such by the stored procedure. For example,

• Strings are never null-terminated.

• CHAR types are blank padded.

• VARCHAR and LONG VARCHAR types have both a defined (maximum) length, and an actual length stored as the first two bytes (SQLCHAR structure).

• DECIMAL (or NUMERIC) types are stored in packed decimal format.

• LOB or UDF types cause a doubled-SQLDA to be sent.

The suggested approach is for the stored procedure to interpret the SQLDA and move all input arguments to host language variables on entry, and from host language variables to the SQLDA on exit. This allows for SQLDA specific code to be localized within the stored procedure.

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