大约有 40,000 项符合查询结果(耗时:0.0184秒) [XML]
How can I check MySQL engine type for a specific table?
...st of all the tables in a database and their engines, use this SQL query:
SELECT TABLE_NAME,
ENGINE
FROM information_schema.TABLES
WHERE TABLE_SCHEMA = 'dbname';
Replace dbname with your database name.
share
...
Check if a class has a member function of a given signature
...her down
Check for member x in a given class. Could be var, func, class, union, or enum:
CREATE_MEMBER_CHECK(x);
bool has_x = has_member_x<class_to_check_for_x>::value;
Check for member function void x():
//Func signature MUST have T as template variable here... simpler this way :\
CREAT...
What's the difference between MyISAM and InnoDB? [duplicate]
... on the table, and while that lock is held, no other session can perform a SELECT or a DML operation on the table.
Those two specific engines you asked about (InnoDB and MyISAM) have different design goals. MySQL also has other storage engines, with their own design goals.
So, in choosing between In...
MySQL Select all columns from one table and some from another table
How do you select all the columns from one table and just some columns from another table using JOIN? In MySQL.
4 Answers
...
How can I search (case-insensitive) in a column using LIKE wildcard?
...
SELECT *
FROM trees
WHERE trees.`title` COLLATE UTF8_GENERAL_CI LIKE '%elm%'
Actually, if you add COLLATE UTF8_GENERAL_CI to your column's definition, you can just omit all these tricks: it will work automatically.
...
What's the difference between array_merge and array + array?
...
The difference is:
The + operator takes the union of the two arrays, whereas the array_merge function takes the union BUT the duplicate keys are overwritten.
share
|
i...
How do I convert from BLOB to TEXT in MySQL?
...
That's unnecessary. Just use SELECT CONVERT(column USING utf8) FROM..... instead of just SELECT column FROM...
share
|
improve this answer
|
...
Differences between INDEX, PRIMARY, UNIQUE, FULLTEXT in MySQL?
...e - which are typically implemented internally using b-trees (allowing for selecting, sorting or ranges starting from left most column) or hash tables (allowing for selection starting from left most column).
Where the other index types are general-purpose, a FULLTEXT index is specialised, in that it...
Difference between two dates in MySQL
...
SELECT TIMEDIFF('2007-12-31 10:02:00','2007-12-30 12:01:01');
-- result: 22:00:59, the difference in HH:MM:SS format
SELECT TIMESTAMPDIFF(SECOND,'2007-12-30 12:01:01','2007-12-31 10:02:00');
-- result: 79259 the differenc...
Duplicating a MySQL table, indices, and data
...ese 2 queries:
CREATE TABLE newtable LIKE oldtable;
INSERT INTO newtable SELECT * FROM oldtable;
To copy just structure and data use this one:
CREATE TABLE tbl_new AS SELECT * FROM tbl_old;
I've asked this before:
Copy a MySQL table including indexes
...
