Insert data

After you create a table, you can use the INSERT statement or other statements to insert data into the table. This topic describes how to insert data into a table by using statements.

Prerequisites

Before you insert data into a table, make sure that:

• You have logged on to a MySQL tenant of OceanBase Database. For more information about how to connect to OceanBase Database, see Connection methods.

  Note

  You can query the oceanbase.DBA_OB_TENANTS view in the sys tenant to confirm the mode of the tenant to which you have logged on.

• You have the INSERT privilege on the target table. For more information about how to view your privileges, see View user privileges. If you do not have the required privileges, contact the administrator. For more information, see Modify user privileges.

Use an INSERT statement to insert data

Use the INSERT statement to insert data into a table based on the following suggestions.

The syntax is as follows:

INSERT INTO table_name (list_of_columns) VALUES (list_of_values);

Suggestions on data insertion

• Before you insert data, we recommend that you learn the information about all columns of the table, including the column types, valid values, and whether NULL values are allowed.

  You can use the DESC statement to query information about columns.

  obclient [test]> DESC test;
  +-------+---------+------+-----+---------+-------+
  | Field | Type    | Null | Key | Default | Extra |
  +-------+---------+------+-----+---------+-------+
  | col1  | int(11) | NO   |     | NULL    |       |
  | col2  | int(11) | YES  |     | NULL    |       |
  +-------+---------+------+-----+---------+-------+
  2 rows in set
  

  • For a NOT NULL column, note that:

    • If the column has a default value, you do not need to specify a value for this column when you insert data. The system will insert the default value into this column if you do not specify a value.

    • If no default value has been specified for the column, you must specify a value for the column when you insert data.

  • For a NULL column, you do not need to specify a value for this column when you insert data. The system will insert a NULL value into this column.

• Before you insert data into a table, we recommend that you learn the information about constraints defined on columns of the table. This is to avoid errors when you insert data.

  You can query the NOT NULL, PRIMARY KEY, and UNIQUE constraints by using the DESC statement. You can query the FOREIGN KEY and CHECK constraints in the information_schema.TABLE_CONSTRAINTS view.

Insert a single row of data

You can use the INSERT statement to insert a single row of data. To insert multiple records, you can execute the single-row insertion statement multiple times. To perform batch insertion, see Insert multiple rows of data in batches.

Assume that the information about the table into which data is to be inserted is as follows:

obclient [test]> CREATE TABLE t_insert(
    id int NOT NULL PRIMARY KEY,
    name varchar(10) NOT NULL,
    value int,
    gmt_create DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
 );
Query OK, 0 rows affected

The id and name columns of the table cannot be empty. The id column is the primary key column with a UNIQUE constraint, and therefore cannot have duplicate values. A default value is specified for the gmt_create column.

Example 1: Insert multiple rows of data into a table by executing the single-row insertion statement multiple times.

A default value is specified for the gmt_create column. Therefore, you do not need to specify a value for this column when you insert data.

obclient [test]> INSERT INTO t_insert(id, name, value)
VALUES (1,'CN',10001);
Query OK, 2 rows affected

obclient [test]> INSERT INTO t_insert(id, name, value)
VALUES(2,'US', 10002);
Query OK, 2 rows affected

If no default value is specified for the gmt_create column, you must specify a value for this column when you insert data by using the following statement:

obclient [test]> INSERT INTO t_insert(id, name, value, gmt_create)
 VALUES (3,'EN', 10003, current_timestamp ());
Query OK, 1 row affected

Insert multiple rows of data in batches

To insert multiple records, you can also use an INSERT statement that contains multiple VALUES. A single multi-row insertion statement is executed faster than multiple single-row insertion statements.

The operation in Example 1 can be completed by using the statement in Example 2.

Example 2: Insert multiple rows of data in batches.

obclient [test]> INSERT INTO t_insert(id, name, value)
  VALUES (1,'CN',10001),(2,'US', 10002);
Query OK, 2 rows affected

To back up a table or copy all records in a table to another table, you can use the INSERT INTO ... SELECT ... FROM statement as the VALUES clause in the INSERT statement for batch insertion.

Example 3: Back up all data in the t_insert table to the t_insert_bak table.

obclient [test]> SELECT * FROM t_insert;
+----+------+-------+---------------------+
| id | name | value | gmt_create          |
+----+------+-------+---------------------+
|  1 | CN   | 10001 | 2022-10-12 15:17:17 |
|  2 | US   | 10002 | 2022-10-12 16:29:16 |
|  3 | EN   | 10003 | 2022-10-12 16:29:26 |
+----+------+-------+---------------------+
3 rows in set

obclient [test]> CREATE TABLE t_insert_bak(
    id number NOT NULL PRIMARY KEY,
    name varchar(10) NOT NULL,
    value number,
    gmt_create DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
 );
Query OK, 0 rows affected

obclient [test]> INSERT INTO t_insert_bak SELECT * FROM t_insert;
Query OK, 2 rows affected

obclient [test]> SELECT * FROM t_insert_bak;
+----+------+-------+---------------------+
| id | name | value | gmt_create          |
+----+------+-------+---------------------+
|  1 | CN   | 10001 | 2022-10-12 15:17:17 |
|  2 | US   | 10002 | 2022-10-12 16:29:16 |
|  3 | EN   | 10003 | 2022-10-12 16:29:26 |
+----+------+-------+---------------------+
3 rows in set

Avoid UNIQUE constraint conflicts

When you insert identical records into a table that has a UNIQUE constraint, the database returns an error. Here is the error message:

obclient [test]> INSERT INTO t_insert(id, name, value) VALUES (3,'UK', 10003),(4, 'JP', 10004);
ERROR 1062 (23000): Duplicate entry '3' for key 'PRIMARY'

You can use the INSERT IGNORE INTO or INSERT INTO ON DUPLICATE KEY UPDATE statement to avoid this error.

Here is an example:

• If you use INSERT IGNORE INTO to avoid constraint conflicts, you can use the IGNORE keyword to ignore the impact of an insertion failure caused by a constraint conflict.

  obclient [test]> INSERT IGNORE INTO t_insert(id, name, value)
      VALUES (3,'UK', 10003),(4, 'JP', 10004);
  Query OK, 1 row affected
  
  obclient [test]> SELECT * FROM t_insert;
  +----+------+-------+---------------------+
  | id | name | value | gmt_create          |
  +----+------+-------+---------------------+
  |  1 | CN   | 10001 | 2022-10-12 15:17:17 |
  |  2 | US   | 10002 | 2022-10-12 16:29:16 |
  |  3 | EN   | 10003 | 2022-10-12 16:29:26 |
  |  4 | JP   | 10004 | 2022-10-12 17:02:52 |
  +----+------+-------+---------------------+
  4 rows in set
  

  In this example, the INSERT IGNORE INTO statement is used. Therefore, the system does not return an error even if (3,'UK', 10003) failed to be inserted.

  Notice

  This method ignores only the error data but does not affect the insert operation.

• If you use INSERT INTO ON DUPLICATE KEY UPDATE to avoid constraint conflicts, you can specify the action to take on duplicate primary keys or unique keys.

  Note

  • ON DUPLICATE KEY UPDATE column_name = expr is specified: If the data to be inserted is duplicate with values of the primary key or unique key, you can use the column_name = expr statement to update the data in conflicting rows of the table. The column_name = expr statement can assign values to one or more columns of the conflicting rows. Separate the columns with commas (,).
  • ON DUPLICATE KEY UPDATE column_name = expr is not specified: If the data to be inserted is duplicate with values of the primary key or unique key, the system returns an error.

  obclient [test]> INSERT INTO t_insert(id, name, value) VALUES (3,'UK', 10003),(5, 'CN', 10005) ON DUPLICATE KEY UPDATE name = VALUES(name);
  Query OK, 1 row affected
  
  obclient [test]> SELECT * FROM t_insert;
  +----+------+-------+---------------------+
  | id | name | value | gmt_create          |
  +----+------+-------+---------------------+
  |  1 | CN   | 10001 | 2022-10-12 16:29:16 |
  |  2 | US   | 10002 | 2022-10-12 15:17:17 |
  |  3 | UK   | 10003 | 2022-10-12 16:29:26 |
  |  4 | JP   | 10004 | 2022-10-12 17:02:52 |
  |  5 | CN   | 10005 | 2022-10-12 17:27:46 |
  +----+------+-------+---------------------+
  5 rows in set
  

  In this example, ON DUPLICATE KEY UPDATE name = VALUES(name) specifies that when the inserted data is duplicate with a value of the primary key, the value of the name column of the conflicting row (3,'EN', 10003) in the original data is updated to the value of the name column of the data to be inserted. For non-conflicting rows, data is normally inserted.

Insert data by using other statements

Besides the INSERT statement, you can use the REPLACE INTO statement instead to insert data into a table without data records or a table with data records but no conflicts with the primary key or unique key constraints. For more information about the REPLACE INTO statement, see REPLACE.

Here are the examples:

• Create a table named t_replace and then use the REPLACE INTO statement to insert data into the table.

  obclient [test]> CREATE TABLE t_replace(
      id int NOT NULL PRIMARY KEY
      , name varchar(10) NOT NULL
      , value int
      ,gmt_create timestamp NOT NULL DEFAULT current_timestamp
  );
  Query OK, 0 rows affected
  
  obclient [test]> REPLACE INTO t_replace VALUES(1,'CN',2001, current_timestamp ());
  Query OK, 1 row affected
  
  obclient [test]> SELECT * FROM t_replace;
  +----+------+-------+---------------------+
  | id | name | value | gmt_create          |
  +----+------+-------+---------------------+
  |  1 | CN   |  2001 | 2022-11-23 09:52:44 |
  +----+------+-------+---------------------+
  1 row in set
  

• Use the REPLACE INTO statement to insert data into the t_replace table that has data records.

  obclient [test]> SELECT * FROM t_replace;
  +----+------+-------+---------------------+
  | id | name | value | gmt_create          |
  +----+------+-------+---------------------+
  |  1 | CN   |  2001 | 2022-03-22 16:13:55 |
  +----+------+-------+---------------------+
  1 row in set
  
  obclient [test]> REPLACE INTO t_replace values(2,'US',2002, current_timestamp ());
  Query OK, 1 row affected
  
  obclient [test]> SELECT * FROM t_replace;
  +----+------+-------+---------------------+
  | id | name | value | gmt_create          |
  +----+------+-------+---------------------+
  |  1 | CN   |  2001 | 2022-11-23 09:52:44 |
  |  2 | US   |  2002 | 2022-11-23 09:53:05 |
  +----+------+-------+---------------------+
  2 rows in set
  

References

• Update data

• Delete data

• Replace data