MySQL 创建索引(Create Index)的方法和语法结构及例子 CREATE INDEX Syntax CREATE [UNIQUE|FULLTEXT|SPATIAL] INDEX index_name [index_type] ON tbl_name (index_col_name,...) [index_type] index_col_name: col_name [(length)] [
For example, this syntax does not work: CREATE TABLE employees ( data JSON, INDEX ((data->>'$.name')) ); The syntax fails because: The ->> operator translates into JSON_UNQUOTE(JSON_EXTRACT(...)). JSON_UNQUOTE() returns a value with a data type of LONGTEXT, and the hidden ...
CREATE TABLE employees ( data JSON, INDEX ((data->>'$.name')) ); The syntax fails because: The ->> operator translates into JSON_UNQUOTE(JSON_EXTRACT(...)). JSON_UNQUOTE() returns a value with a data type of LONGTEXT, and the hidden generated column thus is assigned the same ...
五、创建索引 官网参考手册(5.7)-- CREATE INDEX Syntax 1. 创建表时创建索引 创建名为 idx_name 的普通索引,对唯一性没有限制 CREATETABLEtest2 ( idint(11)NOTNULLAUTO_INCREMENT, namevarchar(255)NOTNULL, numint(11)NOTNULLDEFAULT0, created_attimestampNULLDEFAULTCURRENT_TIMESTAMP,PRIMARYKEY (`id`),...
MySQL创建索引（CreateIndex）的⽅法和语法结构及例 ⼦ CREATE INDEX Syntax CREATE [UNIQUE|FULLTEXT|SPATIAL] INDEX index_name [index_type]ON tbl_name (index_col_name,...)[index_type]index_col_name:col_name [(length)] [ASC | DESC]index_type:USING {BTREE | HASH | RTREE} 复制代码代码...
SHOW INDEX FROM test; 1. 一般查询结果显示的是表格形式,在查询语句后加上 \G 可以将查询结果纵向显示。 上图显示 id 为唯一索引。 五、创建索引 官网参考手册(5.7)-- CREATE INDEX Syntax 1. 创建表时创建索引 创建名为 idx_name 的普通索引,对唯一性没有限制 ...
ft_boolean_syntax + -><()~*:""&| #改变IN BOOLEAN MODE的查询字符,不用重新启动MySQL也不用重建索引 ft_min_word_len 4 #最短的索引字符串,默认值为4,(通常改为1)修改后必须重建索引文件 重新建立索引命令:repair table tablename quick ft_max_word_len 84 #最长的索引字符串,默认值为84,修改后必...
CREATE INDEX Syntax CREATE [UNIQUE|FULLTEXT|SPATIAL] INDEX index_name [index_type] ON tbl_name (index_col_name,...) [index_type] index_col_name: col_name [(length)] [ASC | DESC] index_type: USING {BTREE | HASH | RTREE} 复制代码 代码如下: -- 创建无索引的表格 create table test...
Withcol_name(N)syntax in an index specification for a string column, you can create an index that uses only the firstNcharacters of the column. Indexing only a prefix of column values in this way can make the index file much smaller. When you index a...
CREATE INDEXSyntax CREATE [UNIQUE|FULLTEXT] INDEX index_name ON tbl_name (col_name[(length)],... ) TheCREATE INDEXstatement doesn’t do anything in MySQL prior to Version 3.22. In Version 3.22 or later,CREATE INDEXis mapped to anALTER TABLEstatement to create indexes. SeeSection 6.5.4....