28 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			28 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| drop table if exists t1;
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| create table t1 (id int primary key, n1 int, n2 int, s varchar(20), vs varchar(20), t varchar(256));
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| insert into t1 values (0, NULL, NULL, 'zero', 'zero', 'zero'), (1,1,11, 'one','eleven', 'eleven'),  (2,1,11, 'one','eleven', 'eleven'),  (3,2,11, 'two','eleven', 'eleven'),  (4,2,12, 'two','twevle', 'twelve'),  (5,2,13, 'two','thirteen', 'foo'),  (6,2,13, 'two','thirteen', 'foo'),  (7,2,13, 'two','thirteen', 'bar'),  (8,NULL,13, 'two','thirteen', 'bar'),  (9,2,NULL, 'two','thirteen', 'bar'),  (10,2,13, NULL,'thirteen', 'bar'),  (11,2,13, 'two',NULL, 'bar'),  (12,2,13, 'two','thirteen', NULL);
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| select n1, n2 from t1;
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| n1	n2
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| NULL	NULL
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| 1	11
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| 1	11
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| 2	11
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| 2	12
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| 2	13
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| 2	13
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| 2	13
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| NULL	13
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| 2	NULL
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| 2	13
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| 2	13
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| 2	13
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| select count(distinct n1), count(distinct n2) from t1;
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| count(distinct n1)	count(distinct n2)
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| 2	3
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| select count(n1), count(distinct n1), count(n2), count(distinct n2) from t1;
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| count(n1)	count(distinct n1)	count(n2)	count(distinct n2)
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| 11	2	11	3
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| select count(distinct n1), count(distinct n2), count(n1), count(n2) from t1;
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| count(distinct n1)	count(distinct n2)	count(n1)	count(n2)
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| 2	3	11	11
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