大约有 13,000 项符合查询结果(耗时:0.0249秒) [XML]

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Entity Attribute Value Database vs. strict Relational Model Ecommerce

...uld be domain models. Sort of like a serialization, but you could use SQL selects on indexed text fields. No multiple selects per record. All the "cost" happens in RAM. – Zachary Scott Jun 15 '10 at 3:06 ...
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Get table column names in MySQL?

...DESCRIBE my_table; Or in newer versions you can use INFORMATION_SCHEMA: SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = 'my_database' AND TABLE_NAME = 'my_table'; Or you can use SHOW COLUMNS: SHOW COLUMNS FROM my_table; ...
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Can you create nested WITH clauses for Common Table Expressions?

..., the form of the statement you are looking for would be WITH x AS ( SELECT * FROM MyTable ), y AS ( SELECT * FROM x ) SELECT * FROM y share | improve this answer | ...
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GROUP BY with MAX(DATE) [duplicate]

... to your group by clause, otherwise you need to rethink your query. Try: SELECT t.Train, t.Dest, r.MaxTime FROM ( SELECT Train, MAX(Time) as MaxTime FROM TrainTable GROUP BY Train ) r INNER JOIN TrainTable t ON t.Train = r.Train AND t.Time = r.MaxTime ...
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Shortcuts in Objective-C to concatenate NSStrings

...%@", three, two, one]; technique seems the most elegant. It should be the selected answer. – ekillaby Feb 21 '14 at 19:39  |  show 2 more com...
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Reason for Column is invalid in the select list because it is not contained in either an aggregate f

...c 1 def 1 ghi 2 jkl 2 mno 2 pqr And I do the following query: SELECT a, b FROM T GROUP BY a The output should have two rows, one row where a=1 and a second row where a=2. But what should the value of b show on each of these two rows? There are three possibilities in each case, and no...
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How to get all columns' names for all the tables in MySQL?

... select * from information_schema.columns where table_schema = 'your_db' order by table_name,ordinal_position share | impro...
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How to declare a variable in MySQL?

...at has not been initialized, it has a value of NULL and a type of string. SELECT @var_any_var_name You can initialize a variable using SET or SELECT statement: SET @start = 1, @finish = 10; or SELECT @start := 1, @finish := 10; SELECT * FROM places WHERE place BETWEEN @start AND @finish...
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SQL order string as number

...u can't do that then cast your column value to an integer explicitly with select col from yourtable order by cast(col as unsigned) or implicitly for instance with a mathematical operation which forces a conversion to number select col from yourtable order by col + 0 BTW MySQL converts strings...
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Why .NET String is immutable? [duplicate]

... before StringBuilder becomes more efficient than the equivalent series of concatenations, with their inherent construction). It would be a disadvantage if mutability was part of the purpose of an object (who'd want to be modeled by an Employee object whose salary could never ever change) though so...