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			123 lines
		
	
	
	
		
			3.4 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
			
		
		
	
	
			123 lines
		
	
	
	
		
			3.4 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
| create table t1 (
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|   pk int primary key,
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|   a int,
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|   b int,
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|   c char(10),
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|   d decimal(10, 3),
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|   e real
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| );
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| 
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| insert into t1 values
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| ( 1, 0, 1,    'one',    0.1,  0.001),
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| ( 2, 0, 2,    'two',    0.2,  0.002),
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| ( 3, 0, 3,    'three',  0.3,  0.003),
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| ( 4, 1, 2,    'three',  0.4,  0.004),
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| ( 5, 1, 1,    'two',    0.5,  0.005),
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| ( 6, 1, 1,    'one',    0.6,  0.006),
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| ( 7, 2, NULL, 'n_one',  0.5,  0.007),
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| ( 8, 2, 1,    'n_two',  NULL, 0.008),
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| ( 9, 2, 2,    NULL,     0.7,  0.009),
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| (10, 2, 0,    'n_four', 0.8,  0.010),
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| (11, 2, 10,   NULL,     0.9,  NULL);
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| 
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| select pk,
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|        lead(pk)    over (order by pk),
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|        lead(pk, 1) over (order by pk),
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|        lead(pk, 2) over (order by pk),
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|        lead(pk, 0) over (order by pk),
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|        lead(pk, -1) over (order by pk),
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|        lead(pk, -2) over (order by pk)
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| from t1
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| order by pk asc;
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| 
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| select pk,
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|        lag(pk)    over (order by pk),
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|        lag(pk, 1) over (order by pk),
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|        lag(pk, 2) over (order by pk),
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|        lag(pk, 0) over (order by pk),
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|        lag(pk, -1) over (order by pk),
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|        lag(pk, -2) over (order by pk)
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| from t1
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| order by pk asc;
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| 
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| select pk, pk - 2,
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|        lag(pk, pk - 2) over (order by pk),
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|        lead(pk, pk - 2) over (order by pk)
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| from t1
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| order by pk asc;
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| 
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| select pk, pk - 2,
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|        lag(pk, pk + 2) over (order by pk),
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|        lead(pk, pk + 2) over (order by pk)
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| from t1
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| order by pk asc;
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| 
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| select pk, a,
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|        lead(pk)    over (partition by a order by pk),
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|        lead(pk, 1) over (partition by a order by pk),
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|        lead(pk, 2) over (partition by a order by pk),
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|        lead(pk, 0) over (partition by a order by pk),
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|        lead(pk, -1) over (partition by a order by pk),
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|        lead(pk, -2) over (partition by a order by pk)
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| from t1
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| order by pk asc;
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| 
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| select pk, a,
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|        lag(pk)    over (partition by a order by pk),
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|        lag(pk, 1) over (partition by a order by pk),
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|        lag(pk, 2) over (partition by a order by pk),
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|        lag(pk, 0) over (partition by a order by pk),
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|        lag(pk, -1) over (partition by a order by pk),
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|        lag(pk, -2) over (partition by a order by pk)
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| from t1
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| order by pk asc;
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| 
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| select pk, a, pk - 2,
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|        lag(pk, pk - 2) over (partition by a order by pk),
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|        lead(pk, pk - 2) over (partition by a order by pk),
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|        lag(pk, a - 2) over (partition by a order by pk),
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|        lead(pk, a - 2) over (partition by a order by pk)
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| from t1
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| order by pk asc;
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| 
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| select pk, a, pk - 2,
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|        lag(pk, pk + 2) over (partition by a order by pk),
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|        lead(pk, pk + 2) over (partition by a order by pk),
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|        lag(pk, a + 2) over (partition by a order by pk),
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|        lead(pk, a + 2) over (partition by a order by pk)
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| from t1
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| order by pk asc;
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| 
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| select pk, a, b, c, d, e,
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|            lag(a) over (partition by a order by pk),
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|            lag(b) over (partition by a order by pk),
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|            lag(c) over (partition by a order by pk),
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|            lag(d) over (partition by a order by pk),
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|            lag(e) over (partition by a order by pk)
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| from t1
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| order by pk asc;
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| 
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| select pk, a, b, a+b,
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|        lag(a + b) over (partition by a order by pk)
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| from t1
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| order by pk asc;
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| 
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| select pk, a, b, a+b,
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|        lag(a + b) over (partition by a order by pk) + pk
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| from t1
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| order by pk asc;
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| 
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| --echo #
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| --echo # MDEV-15204 - LAG function doesn't require ORDER BY in OVER clause
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| --echo #
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| --error ER_NO_ORDER_LIST_IN_WINDOW_SPEC
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| select pk,
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|        lag(pk, 1) over ()
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| from t1;
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| 
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| --error ER_NO_ORDER_LIST_IN_WINDOW_SPEC
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| select pk,
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|        lead(pk, 1) over ()
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| from t1;
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| 
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| drop table t1;
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