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What is “the inverse side of the association” in a bidirectional JPA OneToMany/ManyToOne association
...customer. So the customer seems to be the owner of the orders.
But in the SQL world, one item will actually contain a pointer to the other. Since there is 1 customer for N orders, each order contains a foreign key to the customer it belongs to. This is the "connection" and this means the order "own...
MySQL foreign key constraints, cascade delete
... When creating the tables, you need to specify InnoDB or another MySQL engine that's capable of CASCADE operations. Otherwise the MySQL default, MyISAM, will be used and MyISAM does not support CASCADE operations. To do this, just add ENGINE InnoDB before the last ;.
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Reorder / reset auto increment primary key
I have a MySQL table with an auto increment primary key. I deleted some rows in the middle of the table. Now I have, for example, something like this in the ID column: 12, 13, 14, 19, 20. I deleted the 15, 16, 17 and 18 rows.
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Easiest way to copy a table from one database to another?
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If you have shell access you may use mysqldump to dump the content of database1.table1 and pipe it to mysql to database2. The problem here is that table1 is still table1.
mysqldump --user=user1 --password=password1 database1 table1 \
| mysql --user=user2 --passwo...
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...)
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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...
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?
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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 = $...