Informix Error -22559: SQLUNKNOWN is invalid data type, need to be set valid data type.

Cause and resolution

SQLUNKNOWN is invalid data type, need to be set valid data type.

If the database server cannot infer the type of parameter in an expression, the DESCRIBE INPUT statement returns SQLUNKNOWN as the data type. Before statement execution, you must set a valid SQL data type to replace SQLUNKNOWN.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-22559 fires when a DESCRIBE INPUT result's SQLUNKNOWN placeholder type is used without being resolved — per the official guidance, the database server returns SQLUNKNOWN when it can't infer a parameter's type, and the caller must set a valid SQL data type in its place before executing the statement.

An SQLUNKNOWN type from DESCRIBE INPUT left unresolved before statement execution, per the official guidance — the direct, only cause.

Solutions / Resolution

Set a valid SQL data type in place of SQLUNKNOWN before executing the statement, per the official guidance.

Examples

N/A

No specific triggering statement is documented beyond executing with an unresolved SQLUNKNOWN.

Diagnostic Checks

Check the DESCRIBE INPUT output for any parameter still typed SQLUNKNOWN, and set a valid type before execution.

Related Errors / Related Topics

-22554 — "Field type field-type-name has been used out of context." A related system-descriptor error, on a field type used in the wrong context rather than an unresolved SQLUNKNOWN type.

A DESCRIBE INPUT parameter's SQLUNKNOWN type was left unresolved before execution — set a valid SQL data type first.