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Difference Between One-to-Many, Many-to-One and Many-to-Many?
...one side and City is the many side. There will be a column state_id in the table cities.
In unidirectional, Person class will have List<Skill> skills but
Skill will not have Person person. In bidirectional, both
properties are added and it allows you to access a Person given a
skill( i.e. sk...
SQL select join: is it possible to prefix all columns as 'prefix.*'?
I'm wondering if this is possible in SQL. Say you have two tables A and B, and you do a select on table A and join on table B:
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Delete all records in a table of MYSQL in phpMyAdmin
I use wampserver 2.2. When I want to delete all records of a table in phpMyAdmin (select all) it deletes only one record not all records. Why it does not delete all records?
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How to alter a column and change the default value?
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ALTER TABLE foobar_data MODIFY COLUMN col VARCHAR(255) NOT NULL DEFAULT '{}';
A second possibility which does the same (thanks to juergen_d):
ALTER TABLE foobar_data CHANGE COLUMN col col VARCHAR(255) NOT NULL DEFAULT '{}';
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How do I add indices to MySQL tables?
I've got a very large MySQL table with about 150,000 rows of data. Currently, when I try and run
7 Answers
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How to get number of entries in a Lua table?
.... The Lua # operator only counts entries with integer keys, and so does table.getn :
8 Answers
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Query to list number of records in each table in a database
How to list row count of each table in the database. Some equivalent of
21 Answers
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MySQL Insert into multiple tables? (Database normalization?)
I tried searching a way to insert information in multiple tables in the same query, but found out it's impossible?
So I want to insert it by simply using multiple queries i.e;
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Entity Framework. Delete all rows in table
How I can quickly remove all rows in table using Entity Framework?
21 Answers
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What does it mean by select 1 from table?
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SELECT 1 FROM TABLE_NAME means, "Return 1 from the table". It is pretty unremarkable on its own, so normally it will be used with WHERE and often EXISTS (as @gbn notes, this is not necessarily best practice, it is, however, common enough t...