Tablestore:Configure an auto-increment primary key column

Prerequisites

The OTSClient instance is initialized. For more information, see Initialization.

Procedure

1. When you create a table, you cannot set the partition key to an auto-increment primary key column.

   An auto-increment primary key column can only be an integer column. The generated value for an auto-increment primary key column is a 64-bit signed long integer.

2. When you write data to a table, you do not need to specify a specific value for the auto-increment column. Instead, you need only to set the value of the auto-increment column to placeholders.

   If you want to obtain the value of the auto-increment column after data is written to the table, you can set ReturnType to ReturnTypeConst::CONST_PK.

   When you query data, you must specify the values of all primary key columns. To obtain a complete primary key value, you can set ReturnType to ReturnTypeConst::CONST_PK in PutRow, UpdateRow, or BatchWriteRow.

Examples

When you use auto-increment primary key columns, you can call the CreateTable, PutRow, UpdateRow, or BatchWriteRow operation.

1. Create a table

   To create an auto-increment primary key column when you create a table, you must set the attribute of the primary key column to PrimaryKeyOptionConst::CONST_PK_AUTO_INCR.

   function createTable($otsClient) 
   {
       $request = [
           'table_meta' => [
               'table_name' => 'table_name',       // Specify the table name.
               'primary_key_schema' => [
                   ['PK_1', PrimaryKeyTypeConst::CONST_STRING],    // The name of the first primary key column (partition key) is PK_1. The type of the first primary key column is STRING.
                   ['PK_2', PrimaryKeyTypeConst::CONST_INTEGER, PrimaryKeyOptionConst::CONST_PK_AUTO_INCR]
                   // The name of the second primary key column (partition key) is PK_2. The type of the second primary key column is INTEGER. Set this column to the primary key column.
               ]
           ],
           'reserved_throughput' => [
               'capacity_unit' => [         // Set the reserved read throughput to 0 capacity units (CUs) and reserved write throughput to 0 CUs.
                   'read' => 0,
                   'write' => 0
               ]
           ],
           'table_options' => [
               'time_to_live' => -1,             // Specify that data never expires.
               'max_versions' => 1,              // Save only one version.
               'deviation_cell_version_in_sec' => 86400   // Set the max version offset of data. Unit: seconds.
           ]
       ];
       $otsClient->createTable($request);
   }
                       

2. Write data

   When you write data to a table, you do not need to specify a value for the auto-increment column. Instead, you need only to set the value of the auto-increment column to PrimaryKeyTypeConst::CONST_PK_AUTO_INCR.

   function putRow($otsClient)
   {
       $row = [
           'table_name' => 'table_name',
           'primary_key' => [
               ['PK_1', 'Hangzhou'],                      // Set the primary key name and value that are of the list type.
               ['PK_2', null, PrimaryKeyTypeConst::CONST_PK_AUTO_INCR]    // The auto-increment primary key column. You do not need to specify the value. Instead, you need only to set the value of the auto-increment column to PrimaryKeyTypeConst::CONST_PK_AUTO_INCR. Tablestore automatically generates this value.
           ],
           'attribute_columns' => [              // Set the attribute column that is of the list type.
               ['name', 'John'],                  // [The attribute name, attribute value, attribute type, and timestamp]. Ignore the parameters that are not specified.
               ['age', 20],
               ['address', 'Alibaba'],
               ['product', 'OTS'],
               ['married', false]
           ],
           'return_content' => [
               'return_type' => ReturnTypeConst::CONST_PK     // Set return_type to ReturnTypeConst::CONST_PK to return the value of the auto-increment primary key column.
           ]
       ];
       $ret = $otsClient->putRow($row);
       print_r($ret);
   
       $primaryKey = $ret['primary_key'];                  // The obtained primary key value can be passed to operations such as GetRow, UpdateRow, and DeleteRow.
       return $primaryKey;
   }