大约有 46,000 项符合查询结果(耗时:0.0253秒) [XML]

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SQL Server: Examples of PIVOTing String data

...l as numbers. This query will only require the table to be scanned once. SELECT Action, MAX( CASE data WHEN 'View' THEN data ELSE '' END ) ViewCol, MAX( CASE data WHEN 'Edit' THEN data ELSE '' END ) EditCol FROM t GROUP BY Action ...
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The SQL OVER() clause - when and why is it useful?

...ated values and then join it back to the original rowset, i.e. like this: SELECT orig.[Partition], orig.Value, orig.Value * 100.0 / agg.TotalValue AS ValuePercent FROM OriginalRowset orig INNER JOIN ( SELECT [Partition], SUM(Value) AS TotalValue FROM OriginalRowset G...
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Select SQL Server database size

... Try this one - Query: SELECT database_name = DB_NAME(database_id) , log_size_mb = CAST(SUM(CASE WHEN type_desc = 'LOG' THEN size END) * 8. / 1024 AS DECIMAL(8,2)) , row_size_mb = CAST(SUM(CASE WHEN type_desc = 'ROWS' THEN size END) ...
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Clear Text Selection with JavaScript

... if (window.getSelection) { if (window.getSelection().empty) { // Chrome window.getSelection().empty(); } else if (window.getSelection().removeAllRanges) { // Firefox window.getSelection().removeAllRanges(); } } else if (doc...
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SELECT * WHERE NOT EXISTS

...uming these tables should be joined on employeeID, use the following: SELECT * FROM employees e WHERE NOT EXISTS ( SELECT null FROM eotm_dyn d WHERE d.employeeID = e.id ) You can join these tables with a LEFT JOIN keyword and filter out the...
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How to get primary key column in Oracle?

... SELECT cols.table_name, cols.column_name, cols.position, cons.status, cons.owner FROM all_constraints cons, all_cons_columns cols WHERE cols.table_name = 'TABLE_NAME' AND cons.constraint_type = 'P' AND cons.constraint_name = ...
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CSS disable text selection

Currently, I have put this in the body tag to disable text selections: 9 Answers 9 ...
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Select datatype of the field in postgres

...tion_schema (8.4 docs referenced here, but this is not a new feature): =# select column_name, data_type from information_schema.columns -# where table_name = 'config'; column_name | data_type --------------------+----------- id | integer default_printer_id | integer mast...
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SQL Update with row_number()

... One more option UPDATE x SET x.CODE_DEST = x.New_CODE_DEST FROM ( SELECT CODE_DEST, ROW_NUMBER() OVER (ORDER BY [RS_NOM]) AS New_CODE_DEST FROM DESTINATAIRE_TEMP ) x share | im...
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Which is faster/best? SELECT * or SELECT column1, colum2, column3, etc

I've heard that SELECT * is generally bad practice to use when writing SQL commands because it is more efficient to SELECT columns you specifically need. ...