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26 lines
590 B
Markdown
26 lines
590 B
Markdown
# Is It Null Or Not Null?
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In PostgreSQL, the standard way to check if something is `NULL` is like so:
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```sql
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select * as wild_pokemons from pokemons where trainer_id is null;
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```
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To check if something is not null, you just add `not`:
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```sql
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select * as captured_pokemons from pokemons where trainer_id is not null;
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```
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PostgreSQL also comes with `ISNULL` and `NOTNULL` which are non-standard
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ways of doing the same as above:
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```sql
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select * as wild_pokemons from pokemons where trainer_id isnull;
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```
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```sql
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select * as captured_pokemons from pokemons where trainer_id notnull;
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```
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