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68 lines
1.3 KiB
Markdown
68 lines
1.3 KiB
Markdown
# Transform
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```
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<transform> ::=
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[ WITH [ <common-table-expression> [ ,...n ] ]
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[ <cte-lib> [ AS ] <alias> [ ,...n ] ]
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]
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<cmd>
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[ INTO <table>
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| <set-op> [ ( ] <cmd> [ ) ]
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] [ ...n ]
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[ AS OF { NOW
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| <timestamp>
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| n { SECONDS | MINUTES | HOURS | DAYS | WEEKS | MONTHS | YEARS } AGO
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| <inline-scalar>
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}
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]
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```
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`<cte-lib>` pre-built library of `<common-table-expression>`, TBD.
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`INTO <table>` inserts resulting `<table-set>` into `<table>`. Prior `<cmd>` is terminal.
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`AS OF` defaults to `NOW`.
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`AS OF <inline-scalar>` inline Scalar function that returns `<timestamp>`.
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```
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<cmd> ::=
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<delete>
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| <insert>
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| <merge>
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| <query>
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| <update>
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```
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```
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<set-op> ::=
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UNION
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| EXCEPT
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| INTERSECT
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| DIVIDED BY [ WITH REMAINDER ]
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| PASS-THRU
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| NOP
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| TEE
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| MULTEE
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```
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Set operators `UNION`, etc. apply the previous result collection to the next query result or result from nested queries `( ... )`.
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Left paren `(` can only exist singly, but right paren `)` may be stacked to any depth `...)))`.
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```
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<set-functions> ::=
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<cmd> | <set-op>
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```
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API:
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```
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+$ transform
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$:
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%transform
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ctes=(list <common-table-expression>)
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(tree <set-functions>)
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==
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```
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## Exceptions
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`<table>` does not exist
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`GRANT` permission on `<table>` violated
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`AS OF` prior to `<table>` component creation
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