大约有 6,000 项符合查询结果(耗时:0.0338秒) [XML]

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What does it mean by select 1 from table?

...n the EXISTS is ignored and you can write this as per Page 191 of the ANSI SQL 1992 Standard: SELECT * FROM AnotherTable WHERE EXISTS (SELECT 1/0 FROM table WHERE...) share | improve this answe...
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Checking for a null int value from a Java ResultSet

...worth a separate thread on SO imho. (java.sun.com/j2se/1.4.2/docs/api/java/sql/…) – Roman May 27 '10 at 10:58 ...
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MySQL with Node.js

... into Node.js. I come from a PHP background, so I'm fairly used to using MySQL for all my database needs. 9 Answers ...
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Are there disadvantages to using a generic varchar(255) for all text-based fields?

...ld always store 255 characters. But since you tagged this question with MySQL, I'll mention a MySQL-specific tip: as rows are copied from the storage engine layer to the SQL layer, VARCHAR fields are converted to CHAR to gain the advantage of working with fixed-width rows. So the strings in memor...
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How to get the last N records in mongodb?

... order mixed up ... your sort() should be run last, not first (much like a SQL ORDER BY) .find({}).skip(1).limit(50).sort({"date":-1}) – Justin Jenkins Mar 6 '12 at 19:11 ...
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How do I create a PDO parameterized query with a LIKE statement?

... thanks. had similar issue with csharp + Mysql + ODBC using like it would not return any rows using "select * from table where column like '%?%';" but will if I do like you did "select * from table where column like ?;" and set the parameter string so: string frag = $...
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Hibernate throws org.hibernate.AnnotationException: No identifier specified for entity: com..domain.

...otations on it whatsoever - leave it a simple pojo. Update: In regards to SQL views, Hibernate docs write: There is no difference between a view and a base table for a Hibernate mapping. This is transparent at the database level ...
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MySQL vs MySQLi when using PHP [closed]

Which is better, MySQL or MySQLi? And why? Which should I use? 6 Answers 6 ...
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PostgreSQL “DESCRIBE TABLE”

How do you perform the equivalent of Oracle's DESCRIBE TABLE in PostgreSQL (using the psql command)? 22 Answers ...
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Best way to check for “empty or null value”

What is best way to check if value is null or empty string in Postgres sql statements? 10 Answers ...