Created
September 8, 2016 09:33
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SQL Making Sense
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| postgres=# select NULL + 4; | |
| ?column? | |
| ---------- | |
| (1 row) | |
| postgres=# select SUM(foo) from (select NULL::integer as foo UNION all select 1) x; | |
| sum | |
| ----- | |
| 1 | |
| (1 row) | |
| postgres=# select SUM(foo) from (select NULL::integer as foo UNION all select 1) x where foo = 5; | |
| sum | |
| ----- | |
| (1 row) |
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