22 lines
646 B
SQL
22 lines
646 B
SQL
USE test;
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SET autocommit = 0;
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SET @a= -1;
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SET @b = -2;
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START TRANSACTION;
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CREATE TABLE IF NOT EXISTS myCity (a int, b char(20));
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INSERT INTO myCity VALUES (1, 'Milan');
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INSERT INTO myCity VALUES (2, 'London');
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COMMIT;
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-- Now there are two values
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START TRANSACTION;
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DELETE FROM myCity;
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-- Now there are zero values
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SET @a = (SELECT COUNT(1) FROM myCity); -- implicit COMMIT for DELETE operation
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ROLLBACK; -- nothing to roll back
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START TRANSACTION;
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SET @b = (SELECT COUNT(*) FROM myCity); -- implicit COMMIT for empty trx
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START TRANSACTION;
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DROP TABLE myCity;
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SELECT (@a+@b) AS res; -- counts 0+0 ans sets the result to 'res'
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COMMIT;
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