5L4p85ps

1CREATE TABLE testnulls (ID INT)
2INSERT INTO testnulls VALUES (1)
3INSERT INTO testnulls VALUES (2)
4INSERT INTO testnulls VALUES (null)
5
6SELECT count(*) FROM testnulls WHERE ID IS NULL --1
7
8SELECT count(ID) FROM testnulls WHERE ID IS NULL --0
9	
10IF EXISTS (SELECT 1 FROM testnulls WHERE ID IS NULL)
11PRINT 'YES'
12ELSE
13PRINT 'NO'
14	
15SELECT COL1 FROM TABLE1 WHERE COL1 IS NULL AND ROWNUM = 1;
16	
17SELECT TOP 1 COL1 FROM TABLE1 WHERE COL1 IS NULL;
18	
19Column_1 Column_2 Column_3
20-------- -------- --------
211        2        NULL
221        NULL     NULL
235        6        NULL
24	
25select 
26    sum(case when Column_1 is null then 1 else 0 end) as Column_1, 
27    sum(case when Column_2 is null then 1 else 0 end) as Column_2, 
28    sum(case when Column_3 is null then 1 else 0 end) as Column_3,
29from TestTable
30	
31Column_1  Column_2  Column_3
320         1         3
33	
34select 
35    sum(case when Column_1 is null then 0 else 1 end) as Column_1, 
36    sum(case when Column_2 is null then 0 else 1 end) as Column_2, 
37    sum(case when Column_3 is null then 0 else 1 end) as Column_3,
38from TestTable
39	
40select 
41    count(Column_1) as Column_1, 
42    count(Column_2) as Column_2, 
43    count(Column_3) as Column_3,
44from TestTable
45	
46Column_1  Column_2  Column_3
473         2         0
48	
49select count(*) from (select top 1 'There is at least one NULL' AS note from TestTable where Column_3 is NULL) a
50	
51select count(*) from (select top 1 'There is at least one non-NULL' AS note from TestTable where Column_3 is not NULL) a