大约有 44,000 项符合查询结果(耗时:0.0366秒) [XML]

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MySQL get row position in ORDER BY

... Use this: SELECT x.id, x.position, x.name FROM (SELECT t.id, t.name, @rownum := @rownum + 1 AS position FROM TABLE t JOIN (SELECT @rownum := 0) r ORDER BY t.name)...
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postgresql return 0 if returned value is null

...eved for display. Edit Here's an example of COALESCE with your query: SELECT AVG( price ) FROM( SELECT *, cume_dist() OVER ( ORDER BY price DESC ) FROM web_price_scan WHERE listing_Type = 'AARM' AND u_kbalikepartnumbers_id = 1000307 AND ( EXTRACT( DAY FROM ( NOW() - ...
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How do I check if a column is empty or null in MySQL?

... This will select all rows where some_col is NULL or '' (empty string) SELECT * FROM table WHERE some_col IS NULL OR some_col = ''; share | ...
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Finding duplicate values in a SQL table

... SELECT name, email, COUNT(*) FROM users GROUP BY name, email HAVING COUNT(*) > 1 Simply group on both of the columns. Note: the older ANSI standard is to have all non-aggregated columns in the GROUP BY ...
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SQL Server loop - how do I loop through a set of records

how do I loop through a set of records from a select? 8 Answers 8 ...
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Removing duplicate rows from table in Oracle

... Use the rowid pseudocolumn. DELETE FROM your_table WHERE rowid not in (SELECT MIN(rowid) FROM your_table GROUP BY column1, column2, column3); Where column1, column2, and column3 make up the identifying key for each record. You might list all your columns. ...
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MySQL “NOT IN” query

... To use IN, you must have a set, use this syntax instead: SELECT * FROM Table1 WHERE Table1.principal NOT IN (SELECT principal FROM table2) share | improve this answer | ...
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Is there any difference between GROUP BY and DISTINCT

...CT and distinct by UNION cause an oracle error, but GROUP BY worked; I was selecting only 1 column from a view and not using any aggregation; I'm still baffled why it required it, but it does confirm there is some difference in the execution. As others point out, it also lets you GROUP BY columns no...
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T-SQL: Opposite to string concatenation - how to split string into multiple records [duplicate]

...12)) RETURNS table AS RETURN ( WITH Pieces(pn, start, stop) AS ( SELECT 1, 1, CHARINDEX(@sep, @s) UNION ALL SELECT pn + 1, stop + 1, CHARINDEX(@sep, @s, stop + 1) FROM Pieces WHERE stop > 0 ) SELECT pn, SUBSTRING(@s, start, CASE WHEN stop > 0 THE...
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In MySQL, how to copy the content of one table to another table within the same database?

... INSERT INTO TARGET_TABLE SELECT * FROM SOURCE_TABLE; EDIT: or if the tables have different structures you can also: INSERT INTO TARGET_TABLE (`col1`,`col2`) SELECT `col1`,`col2` FROM SOURCE_TABLE; EDIT: to constrain this.. INSERT INTO TARGET_TAB...