DECLARE
DECLARE
DECLARE — define a cursor
Synopsis
DECLARE cursor_name [ BINARY ] [ ASENSITIVE | INSENSITIVE ] [ [ NO ] SCROLL ] CURSOR [ { WITH | WITHOUT } HOLD ] FOR prepared_name
DECLARE cursor_name [ BINARY ] [ ASENSITIVE | INSENSITIVE ] [ [ NO ] SCROLL ] CURSOR [ { WITH | WITHOUT } HOLD ] FOR queryDescription
DECLARE declares a cursor for iterating over the result set of a prepared statement. This command has slightly different semantics from the direct SQL command DECLARE: Whereas the latter executes a query and prepares the result set for retrieval, this embedded SQL command merely declares a name as a “loop variable” for iterating over the result set of a query; the actual execution happens when the cursor is opened with the OPEN command.
Parameters
cursor_name
A cursor name, case sensitive. This can be an SQL identifier or a host variable.
prepared_name
The name of a prepared query, either as an SQL identifier or a host variable.
query
A SELECT or VALUES command which will provide the rows to be returned by the cursor.
For the meaning of the cursor options, see DECLARE.
Examples
Examples declaring a cursor for a query:
An example declaring a cursor for a prepared statement:
Compatibility
DECLARE is specified in the SQL standard.
See Also
原文:PostgreSQL 15.19 Documentation(英文原文,待翻譯)
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