Tablestore:Conditional update

Update data by using row existence conditions

The following sample code provides an example on how to update a row based on the primary key. If the specified row exists, the update is successful. Otherwise, the update fails.

updateRowRequest := new(tablestore.UpdateRowRequest)
updateRowChange := new(tablestore.UpdateRowChange)
updateRowChange.TableName = tableName
updatePk := new(tablestore.PrimaryKey)
updatePk.AddPrimaryKeyColumn("pk1", "pk1value1")
updatePk.AddPrimaryKeyColumn("pk2", int64(2))
updatePk.AddPrimaryKeyColumn("pk3", []byte("pk3"))
updateRowChange.PrimaryKey = updatePk
updateRowChange.DeleteColumn("col1")            // Delete the col1 column. 
updateRowChange.PutColumn("col2", int64(77))    // Add the col2 column whose value is 77. 
updateRowChange.PutColumn("col4", "newcol3")    // Add the col4 column whose value is "newcol3". 
// Specify that the row is expected to exist. 
updateRowChange.SetCondition(tablestore.RowExistenceExpectation_EXPECT_EXIST)
updateRowRequest.UpdateRowChange = updateRowChange
_, err := client.UpdateRow(updateRowRequest)
if err != nil {
    fmt.Println("update failed with error:", err)
} else {
    fmt.Println("update row finished")
}

Update data by using row existence conditions and column-based conditions

• Update a row by using conditions

  updateRowRequest := new(tablestore.UpdateRowRequest)
  updateRowChange := new(tablestore.UpdateRowChange)
  updateRowChange.TableName = tableName
  updatePk := new(tablestore.PrimaryKey)
  updatePk.AddPrimaryKeyColumn("pk1", "pk1value1")
  updateRowChange.PrimaryKey = updatePk
  updateRowChange.PutColumn("col2", int64(77)) // Add the col2 column whose value is 77. 
  // Specify that the expected value of the col5 column is 3. 
  clCondition1 := tablestore.NewSingleColumnCondition("col5", tablestore.CT_EQUAL, int64(3))
  // The default value of the FilterIfMissing parameter is false, which specifies that if the column does not exist in a row, the condition check is passed. 
  // If you want to specify that the condition check fails if the column does not exist in a row, set the FilterIfMissing parameter to true. 
  //clCondition1.FilterIfMissing = true
  // Specify that the row is expected to exist. 
  updateRowChange.SetCondition(tablestore.RowExistenceExpectation_EXPECT_EXIST)
  updateRowChange.SetColumnCondition(clCondition1)
  updateRowRequest.UpdateRowChange = updateRowChange
  _, err := client.UpdateRow(updateRowRequest)
  if err != nil {
      fmt.Println("update failed with error:", err)
  } else {
      fmt.Println("update row finished")
  }

• Delete a row by using conditions

  The following sample code provides an example on how to delete a row based on the primary key. If the specified row exists and the value of the col2 column is 3, the update is successful. Otherwise, the update fails.

  deleteRowReq := new(tablestore.DeleteRowRequest)
  deleteRowReq.DeleteRowChange = new(tablestore.DeleteRowChange)
  deleteRowReq.DeleteRowChange.TableName = tableName
  deletePk := new(tablestore.PrimaryKey)
  deletePk.AddPrimaryKeyColumn("pk1", "pk1value1")
  deletePk.AddPrimaryKeyColumn("pk2", int64(2))
  deletePk.AddPrimaryKeyColumn("pk3", []byte("pk3"))
  deleteRowReq.DeleteRowChange.PrimaryKey = deletePk
  
  // Specify that the row is expected to exist. 
  deleteRowReq.DeleteRowChange.SetCondition(tablestore.RowExistenceExpectation_EXPECT_EXIST)
  // Specify that the expected value of the col2 column is 3. 
  clCondition1 := tablestore.NewSingleColumnCondition("col2", tablestore.CT_EQUAL, int64(3))
  // The default value of the FilterIfMissing parameter is false, which specifies that if the column does not exist in a row, the condition check is passed. 
  // If you want to specify that the condition check fails if the column does not exist in a row, set the FilterIfMissing parameter to true. 
  //clCondition1.FilterIfMissing = true
  deleteRowReq.DeleteRowChange.SetColumnCondition(clCondition1)
  _, err := client.DeleteRow(deleteRowReq)
  if err != nil {
      fmt.Println("delete failed with error:", err)
  } else {
      fmt.Println("delete row finished")
  }