works:programmer:db-postgres:index
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works:programmer:db-postgres:index [2020/05/05 15:28] Chugreev Eugene [Индексы] |
works:programmer:db-postgres:index [2020/05/05 15:34] (current) Chugreev Eugene |
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| CREATE UNIQUE INDEX users_username_lower ON users ((lower(username))); | CREATE UNIQUE INDEX users_username_lower ON users ((lower(username))); | ||
| </ | </ | ||
| + | |||
| + | ===== Битовые операции ===== | ||
| + | <code sql> | ||
| + | -- Где содержит бит 1 | ||
| + | WHERE " | ||
| + | -- Где не сожержит бит 2 | ||
| + | WHERE " | ||
| + | |||
| + | -- Установить 1й бит | ||
| + | SET " | ||
| + | |||
| + | -- Снять 2й бит | ||
| + | SET " | ||
| + | |||
| + | </ | ||
| + | |||
| + | |||
works/programmer/db-postgres/index.1588692532.txt.gz · Last modified: 2020/05/05 15:28 by Chugreev Eugene
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