128 lines
3.9 KiB
Plaintext
128 lines
3.9 KiB
Plaintext
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DROP TABLE IF EXISTS t1;
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CREATE TABLE t1(c1 CHAR(100) NULL);
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INSERT INTO t1 (c1) VALUES('NULL');
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INSERT INTO t1 (c1) VALUES('');
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INSERT INTO t1 (c1) VALUES('x');
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INSERT INTO t1 (c1) VALUES('123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.');
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SELECT * FROM t1;
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c1
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NULL
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x
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123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.
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SELECT COUNT(c1) AS total_rows FROM t1;
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total_rows
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4
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SELECT COUNT(c1) AS null_rows FROM t1 WHERE c1 IS NULL;
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null_rows
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0
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SELECT COUNT(c1) AS not_null_rows FROM t1 WHERE c1 IS NOT NULL;
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not_null_rows
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4
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DROP TABLE t1;
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CREATE TABLE t1(c1 VARCHAR(100) NULL);
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INSERT INTO t1 (c1) VALUES('NULL');
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INSERT INTO t1 (c1) VALUES('');
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INSERT INTO t1 (c1) VALUES('x');
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INSERT INTO t1 (c1) VALUES('123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.');
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SELECT * FROM t1;
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c1
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NULL
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x
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123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.
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SELECT COUNT(c1) AS total_rows FROM t1;
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total_rows
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4
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SELECT COUNT(c1) AS null_rows FROM t1 WHERE c1 IS NULL;
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null_rows
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0
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SELECT COUNT(c1) AS not_null_rows FROM t1 WHERE c1 IS NOT NULL;
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not_null_rows
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4
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DROP TABLE t1;
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CREATE TABLE t1(c1 BINARY(100) NULL);
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INSERT INTO t1 (c1) VALUES('NULL');
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INSERT INTO t1 (c1) VALUES('');
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INSERT INTO t1 (c1) VALUES('x');
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INSERT INTO t1 (c1) VALUES('123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.');
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SELECT * FROM t1;
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c1
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NULL |