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PDO closing connection
Just a rather simple question with regards to PDO compared to MySQLi.
5 Answers
5
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Unioning two tables with different number of columns
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MySQL ON DUPLICATE KEY UPDATE for multiple rows insert in single query
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INSERT INTO ... ON DUPLICATE KEY UPDATE will only work for MYSQL, not for SQL Server.
for SQL server, the way to work around this is to first declare a temp table, insert value to that temp table, and then use MERGE
Like this:
declare @Source table
(
name varchar(30),
age decimal(...
拉里佩奇23条箴言帮你度过创业低谷 - 资讯 - 清泛网 - 专注C/C++及内核技术
...VCR也没能让电影院关门。
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不是所有人都想要创造一辆无人驾驶车，或者清洁能源，或者解决十亿人的痛点。但在我内心，有一份...
MySQL - How to select data by string length
Is there a MySQL function to do this (of course instead of string_length )?
6 Answers
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MySQL Select all columns from one table and some from another table
...mns from one table and just some columns from another table using JOIN? In MySQL.
4 Answers
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File Hash 扩展：文件哈希计算和 Base64 编码文件，sha256、sha512 哈希 ·...
...全文件传输验证
备份文件一致性检查
文件去重比较
密码存储（建议使用加盐哈希）
相关功能
可以使用 Juan Antonio 的 Terminal 扩展 通过 Linux 命令获取文件的 SHA256 哈希：
sha256sum /absolute/path/to/file
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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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Are there disadvantages to using a generic varchar(255) for all text-based fields?
...ould 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 mem...
MySQL Results as comma separated list
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The intent is fine and MySQL will allow this, but be careful (generally) with your use of GROUP BY. The items in the select list need to be valid aggregates in the context of the GROUP BY clause. In this case, p.name is not strictly valid. Any d...