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Possible to perform cross-database queries with PostgreSQL?
... executes a query in a remote database
dblink executes a query (usually a SELECT, but it can be any SQL
statement that returns rows) in a remote database.
When two text arguments are given, the first one is first looked up as
a persistent connection's name; if found, the command is executed on
that...
Alter MySQL table to add comments on columns
...
Script for all fields on database:
SELECT
table_name,
column_name,
CONCAT('ALTER TABLE `',
TABLE_SCHEMA,
'`.`',
table_name,
'` CHANGE `',
column_name,
'` `',
column_name,
'` ',
column_typ...
App Inventor 2 拓展参考文档 · App Inventor 2 中文网
...理
【FTP】App Inventor 2 FTP 上传下载全方案总结
【MD5、密码安全】Encrypt.Security 安全性扩展：MD5哈希，SHA1和SHA256哈希，AES加密/解密，RSA加密/解密，BASE64编码/解码（常用功能已内置为加密签名）
【AES加解密】MareshaAES 拓展：AES...
How to select the nth row in a SQL database table?
I'm interested in learning some (ideally) database agnostic ways of selecting the n th row from a database table. It would also be interesting to see how this can be achieved using the native functionality of the following databases:
...
Location of my.cnf file on macOS
...m there, MySQLWorkbench can create them for you by:
Opening a connection
Selecting the 'Options File' under 'INSTANCE' in the menu.
MySQLWorkbench will search for my.cnf and if it can't find it, it'll create it for you
sh...
What is the use of the square brackets [] in sql statements?
...
sql also uses square brackets in the like-operator of a select query to limit results using regular expressions. codeproject.com/Articles/33941/SQL-LIKE-Operator
– Jens Frandsen
Sep 4 '13 at 18:49
...
How to store arrays in MySQL?
... retrieve a person and all of their fruit you can do something like this:
SELECT p.*, f.*
FROM person p
INNER JOIN person_fruit pf
ON pf.person_id = p.id
INNER JOIN fruits f
ON f.fruit_name = pf.fruit_name
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PostgreSQL Autoincrement
...RT INTO foo (bar) values ('blah');
INSERT INTO foo (bar) values ('blah');
SELECT * FROM foo;
1,blah
2,blah
SERIAL is just a create table time macro around sequences. You can not alter SERIAL onto an existing column.
sha...
Insert auto increment primary key to existing table
...etrieve it by id immediately, MySQL offers LAST_INSERT_ID() for that value SELECT * FROM table_name WHERE id = LAST_INSERT_ID() and most programming language APIs offer some function/method to return that value in the application code.
– Michael Berkowski
Jan 2...
Cast from VARCHAR to INT - MySQL
...NED [INTEGER]
TIME
UNSIGNED [INTEGER]
Therefore, you should use:
SELECT CAST(PROD_CODE AS UNSIGNED) FROM PRODUCT
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