by kevin
5.
十一月 2014 23:16
>
碰到一个恶心的问题：
无法保存包含中文的字符串，查了很久，就懂的是字符集的问题。
mysql的字符集在server，database，table，column都可以定义。
查看字符集：
数据库级别
1: SELECT default_character_set_name FROM information_schema.SCHEMATA S
2: WHERE schema_name = "schemaname";
表级别
1: SELECT CCSA.character_set_name FROM information_schema.`TABLES` T,
2: information_schema.`COLLATION_CHARACTER_SET_APPLICABILITY` CCSA
3: WHERE CCSA.collation_name = T.table_collation
4: AND T.table_schema = "schemaname"
5: AND T.table_name = "tablename";
列级别
1: SELECT character_set_name FROM information_schema.`COLUMNS` C
2: WHERE table_schema = "schemaname"
3: AND table_name = "tablename"
4: AND column_name = "columnname";
修改数据库字符集：
1: ALTER DATABASE db_name DEFAULT CHARACTER SET character_name [COLLATE ...];
把表默认的字符集和所有字符列（CHAR,VARCHAR,TEXT）改为新的字符集：
1: ALTER TABLE tbl_name CONVERT TO CHARACTER SET character_name [COLLATE ...]
只是修改表的默认字符集：
1: ALTER TABLE tbl_name DEFAULT CHARACTER SET character_name [COLLATE...];
修改列的字符集：
1: ALTER TABLE tbl_name CHANGE c_name c_name CHARACTER SET character_name [COLLATE ...];