SQL error codes.
Attempting to execute most InterSystems SQL operations issues an SQLCODE value. The SQLCODE values issued are 0, 100, and negative integer values.
SQLCODE=0 indicates successful completion of an SQL operation. For a SELECT statement, this usually means the successful retrieval of data from a table. However, if the SELECT performs an aggregate operation, (for example: SELECT SUM(myfield)) the aggregate operation is successful and an SQLCODE=0 is issued even when there is no data in myfield; in this case SUM returns NULL and %ROWCOUNT=1.
SQLCODE=100 indicates that the SQL operation was successful, but found no data to act upon. This can occur for a number of reasons. For a SELECT these include: the specified table contains no data; the table contains no data that satisfies the query criteria; or row retrieval has reached the final row of the table. For an UPDATE or DELETE these include: the specified table contains no data; or the table contains no row of data that satisfies the WHERE clause criteria. In these cases %ROWCOUNT=0.
SQLCODE=-n indicates an error. The negative integer value specifies the kind of error that occurred. SQLCODE=-400 is a general purpose fatal error code.
For further details on SQLCODE error codes and the corresponding error messages, and a full list of SQLCODE error code values, refer to SQL Error Messages.