25 lines
1.1 KiB
PHP
25 lines
1.1 KiB
PHP
UPDATE statement syntax:
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<div class='sql'>
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<pre>
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UPDATE <i>component_name</i>
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SET <i>col_name1</i>=<i>expr1</i> [, <i>col_name2</i>=<i>expr2</i> ...]
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[WHERE <i>where_condition</i>]
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[ORDER BY ...]
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[LIMIT <i>record_count</i>]
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</pre>
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</div>
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<ul>
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<li \>The UPDATE statement updates columns of existing records in <i>component_name</i> with new values and returns the number of affected records.
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<li \>The SET clause indicates which columns to modify and the values they should be given.
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<li \>The optional WHERE clause specifies the conditions that identify which records to update.
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Without WHERE clause, all records are updated.
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<li \>The optional ORDER BY clause specifies the order in which the records are being updated.
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<li \>The LIMIT clause places a limit on the number of records that can be updated. You can use LIMIT row_count to restrict the scope of the UPDATE.
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A LIMIT clause is a <b>rows-matched restriction</b> not a rows-changed restriction.
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The statement stops as soon as it has found <i>record_count</i> rows that satisfy the WHERE clause, whether or not they actually were changed.
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</ul>
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