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28 lines
611 B
Plaintext
28 lines
611 B
Plaintext
SQL Language Extension: NULLIF
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Function:
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Return a NULL value for a sub-expression if it has a specific value
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otherwise return the value of the sub-expression
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Author:
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Arno Brinkman <firebird@abvisie.nl>
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Format:
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<case abbreviation> ::=
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NULLIF <left paren> <value expression> <comma> <value expression> <right paren>
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Syntax Rules:
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1) NULLIF (V1, V2) is equivalent to the following <case specification>:
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CASE WHEN V1 = V2 THEN NULL ELSE V1 END
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Notes:
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See also README.data_type_results_of_aggregations.txt
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Examples:
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A)
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UPDATE PRODUCTS
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SET STOCK = NULLIF(STOCK,0)
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