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In PHP with PDO, how to check the final SQL parametrized query? [duplicate]
..... and finally EXECUTE ....
You won't be able to get some SQL string like SELECT * FROM ..., even if it would produce equivalent results, because no such query was ever actually sent to the database.
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What is cardinality in MySQL?
...ow cardinality column with only 2 possible values as the index will not be selective enough to be used.
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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.
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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
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How can I search (case-insensitive) in a column using LIKE wildcard?
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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.
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How do I convert from BLOB to TEXT in MySQL?
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That's unnecessary. Just use SELECT CONVERT(column USING utf8) FROM..... instead of just SELECT column FROM...
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Difference between two dates in MySQL
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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...
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...
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
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