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CREATE INDEX index_name ON table_name (column_list) CREATE UNIQUE INDEX index_name ON table_name (column_list) 1. 2. 3. table_name、index_name和column_list具有与ALTER TABLE语句中相同的含义,索引名不可选。另外,不能用CREATE INDEX语句创建PRIMARY KEY索引。 3、删除索引 可利用ALTER TABLE或DROP ...
InnoDB storage engine incorporates an internal feature known as the Implicit Primary Key. This feature automatically generates a hidden clustered index named GEN_CLUST_INDEX on a generated column called DB_ROW_ID. Implicit Primary Key is generated when a table is created without a PRIMARY KEY or ...
PRIMARY KEY (`ID_MSG`,`RECEIVED_DATE`), KEY `Idx_NUM_CERTIFICATE` (`NUM_CERTIFICATE`) USING BTREE, KEY `Idx_ID_CONVERSATION` (`ID_CONVERSATION`) USING BTREE, KEY `Idx_TREATMENT_STATE` (`TREATMENT_STATE`) USING BTREE, KEY `Idx_CHECKED_RESULT` (`CHECKED_RESULT`) ...
It is a good practice to add a primary key to every table. When you add a primary key to a table, PostgreSQL creates a unique B-tree index on the column or a group of columns used to define the primary key. Technically, a primary key constraint is the combination of a not-null con...
istruewing@chilla.local +5 -0Bug#24985- UTF8 ENUM primary key on MEMORY using BTREE causes incorrect duplicate entries Keys for a BTREE index on an ENUM column of a MEMORY table with character set UTF8 were computed incorrectly. Many different column values got the same key value. Apart ...
Set any column of a partitioned table as the primary key,PolarDB:In PostgreSQL, the primary key of a partitioned table must come from partition keys and cannot be referenced as a foreign key. PolarDB for PostgreSQL allows you to set any column of a parti
1. Use the .ini file (the configparser package of Python can parse this type of configuration file) to save the configuration information about the database connection. 2. Add SSL connection parameters ca, key and cert to the connection options. a. ssl_disabled: specifies whether to enable ...
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To prove that I really have assigned the primary key, I also made a "SHOW INDEX FROM myTable", giving the following info: Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment myTable 0 PRIMARY 1 DATUM A BTREE myTable 0 PR...