大约有 7,000 项符合查询结果（耗时：0.0193秒） [XML]
How to add a primary key to a MySQL table?
...
mysql doesn't recognize MODIFY as proper statement(at least in XAMPP, InnoDB)
– LMD
Jul 13 '18 at 18:25
...
Difference between Key, Primary Key, Unique Key and Index in MySQL
...
KEY and INDEX are synonyms in MySQL. They mean the same thing. In databases you would use indexes to improve the speed of data retrieval. An index is typically created on columns used in JOIN, WHERE, and ORDER BY clauses.
Imagine you have a table called...
How do I convert from BLOB to TEXT in MySQL?
I have a whole lot of records where text has been stored in a blob in MySQL. For ease of handling I'd like to change the format in the database to TEXT... Any ideas how easily to make the change so as not to interrupt the data - I guess it will need to be encoded properly?
...
Why is it bad style to `rescue Exception => e` in Ruby?
... You can also ADAPTER_ERRORS = [::ActiveRecord::StatementInvalid, PGError, Mysql::Error, Mysql2::Error, ::ActiveRecord::JDBCError, SQLite3::Exception] and then rescue *ADAPTER_ERRORS => e
– j_mcnally
Feb 27 '14 at 2:19
...
Select all columns except one in MySQL?
... trying to use a select statement to get all of the columns from a certain MySQL table except one. Is there a simple way to do this?
...
How do write IF ELSE statement in a MySQL query
How do I write an IF ELSE statement in a MySQL query?
5 Answers
5
...
MySQL: ignore errors when importing?
...
Use the --force (-f) flag on your mysql import. Rather than stopping on the offending statement, MySQL will continue and just log the errors to the console.
For example:
mysql -u userName -p -f -D dbName < script.sql
...
TINYTEXT, TEXT, MEDIUMTEXT, and LONGTEXT maximum storage sizes
Per the MySQL docs , there are four TEXT types:
4 Answers
4
...
一个故事告诉你比特币的原理及运作机制 - 创意 - 清泛网 - 专注C/C++及内核技术
...这样以物易物实在太不方便了，于是村子全员开会，讨论如何解决这个问题。有人提议，以便于分割且稀有的东西，例如黄金，作为一般等价物，把其它物品和黄金的对应关系编成一张表格，例如一克黄金对应一只羊，一克黄金...
How to add not null constraint to existing column in MySQL
...
Oddly I was getting an error (MySQL 5.6, Workbench 6.3) changing/modifying a column I'd named null_heart_rate_count, error was #1138, Invalid use of NULL value. I had to drop and add the column instead.
– William T. Mallard
...