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56 lines
1.5 KiB
Plaintext
56 lines
1.5 KiB
Plaintext
SQL Language Extension: EXECUTE BLOCK
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Function:
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Allow execute PL-SQL block as if it is stored procedure.
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Supports input and output parameters
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Autor:
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Vlad Khorsun <hvlad at users.sourceforge.net>
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Syntax:
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EXECUTE BLOCK [ (param datatype = ?, param datatype = ?, ...) ]
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[ RETURNS (param datatype, param datatype, ...) }
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AS
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[DECLARE VARIABLE var datatype; ...]
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BEGIN
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...
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END
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Client-side:
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The call isc_dsql_sql_info with parameter isc_info_sql_stmt_type returns
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- isc_info_sql_stmt_select, if block has output parameters.
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Semantics of a call is similar to SELECT query - client has open cursor,
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can fetch data from it, and must close it after use.
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- isc_info_sql_stmt_exec_procedure, if block has no output parameters.
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Semantics of a call is similar to EXECUTE query - client has no cursor,
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execution runs until first SUSPEND or end of block
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The client should preprocess only head of the SQL statement or use '?'
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instead of ':' as parameter indicator because in a body of the block may be links
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to local variables and \ or parameters with a colon ahead.
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Example:
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User SQL is
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EXECUTE BLOCK (X INTEGER = :X) RETURNS (Y VARCHAR)
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AS
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DECLARE V INTEGER;
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BEGIN
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INSERT INTO T(...) VALUES (... :X ...);
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SELECT ... FROM T INTO :Y;
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SUSPEND;
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END
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Preprocessed SQL is
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EXECUTE BLOCK (X INTEGER = ?) RETURNS (Y VARCHAR)
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AS
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DECLARE V INTEGER;
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BEGIN
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INSERT INTO T(...) VALUES (... :X ...);
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SELECT ... FROM T INTO :Y;
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SUSPEND;
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END
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