Use an auto-increment primary key column - Tablestore SDK for Go - Tablestore

Use the Tablestore SDK for Go to configure a non-partition primary key column as an auto-increment column when you create a table and obtain the server-generated value when you write data.

Prerequisites

Install the Tablestore SDK for Go and initialize the client.

Description

To use an auto-increment primary key column, configure the column, use an auto-increment placeholder when you write a row, and obtain the generated value from the response.

Note

Only a non-partition primary key column can be configured as an auto-increment column, and the configuration can be specified only when the table is created. The column must be of the INTEGER type. Each table can have at most one auto-increment column. The server generates signed 64-bit integers.

The values are unique and strictly increasing within the same partition key but are not necessarily consecutive. Auto-increment primary key columns and local transactions cannot be used together.

Configure an auto-increment primary key column

When you create a table, call AddPrimaryKeyColumnOption and set the primary key option to AUTO_INCREMENT.

The following sample creates the example_table table. The user_id column is the partition key, and the record_id column is an auto-increment primary key column.

tableMeta := &tablestore.TableMeta{TableName: "example_table"}
tableMeta.AddPrimaryKeyColumn("user_id", tablestore.PrimaryKeyType_STRING)
tableMeta.AddPrimaryKeyColumnOption(
    "record_id",
    tablestore.PrimaryKeyType_INTEGER,
    tablestore.AUTO_INCREMENT,
)

request := &tablestore.CreateTableRequest{
    TableMeta:          tableMeta,
    TableOption:        &tablestore.TableOption{TimeToAlive: -1, MaxVersion: 1},
    ReservedThroughput: &tablestore.ReservedThroughput{},
}

_, err := client.CreateTable(request)
if err != nil {
    log.Fatal(err)
}

Wait until the table is loaded before you write data.

Write data and obtain the generated value

When you write data, call AddPrimaryKeyColumnWithAutoIncrement to set the placeholder and call SetReturnPk to return the complete primary key that contains the generated value. For an auto-increment write, the row existence condition must be set to RowExistenceExpectation_IGNORE.

The following sample writes a row and obtains the server-generated record_id value.

primaryKey := &tablestore.PrimaryKey{}
primaryKey.AddPrimaryKeyColumn("user_id", "user-a")
primaryKey.AddPrimaryKeyColumnWithAutoIncrement("record_id")

change := &tablestore.PutRowChange{
    TableName:  "example_table",
    PrimaryKey: primaryKey,
}
change.AddColumn("status", "created")
change.SetCondition(tablestore.RowExistenceExpectation_IGNORE)
change.SetReturnPk()

response, err := client.PutRow(&tablestore.PutRowRequest{PutRowChange: change})
if err != nil {
    log.Fatal(err)
}

fmt.Println(response.PrimaryKey)

Parameters

Auto-increment primary key column

PrimaryKeySchema contains the following parameters related to auto-increment primary key columns.

Name	Type	Description
Name (required)	`string`	The name of the auto-increment primary key column.
Type (required)	`PrimaryKeyType`	Set this parameter to `PrimaryKeyType_INTEGER`.
Option (required)	`PrimaryKeyOption`	Set this parameter to `AUTO_INCREMENT`.

Write configuration

PutRowChange contains the following parameters related to auto-increment primary key columns.

Name	Type	Description
PrimaryKey (required)	`*PrimaryKey`	The primary key of the row. Call `AddPrimaryKeyColumnWithAutoIncrement` to set the placeholder for the auto-increment column.
Condition (required)	`*RowCondition`	The row existence condition. Set this parameter to `RowExistenceExpectation_IGNORE` for an auto-increment write.
ReturnType (optional)	`ReturnType`	The return type. Default value: `ReturnType_RT_NONE`, which does not return primary key information. Call `SetReturnPk` to set the value to `ReturnType_RT_PK` and return the complete primary key that contains the generated value.

Response

The following field in PutRowResponse is directly related to auto-increment primary key columns.

Field	Type	Description
`PrimaryKey`	`PrimaryKey`	The complete primary key of the written row. This field is returned only when `ReturnType_RT_PK` is specified and contains the server-generated value.