Inserting rows with an MR_COUNTER column
While data is inserted in a multi-region table with an MR_COUNTER column, the system
generates a default value of 0 for the MR_COUNTER column value in the
following two cases.
- When the keyword
DEFAULis used in the insert_clause for the MR_COUNTER column. - When the MR_COUNTER column is skipped in the INSERT clause.
Example 1: Specifying DEFAULT clause while inserting data into an MR_COUNTER column
CREATE Table myTable( name STRING,
count INTEGER AS MR_COUNTER,
PRIMARY KEY(name)) IN REGIONS DEN,LONINSERT INTO myTable VALUES ("Bob", DEFAULT)SELECT * FROM myTableOutput:{"name":"Bob","count":0}Example 2: Skip the MR_COUNTER column while inserting data into a multi-region table
CREATE Table myTable( name STRING,
count INTEGER AS MR_COUNTER,
PRIMARY KEY(name)) IN REGIONS DEN,LONINSERT INTO myTable(name) VALUES ("Chris')SELECT * FROM myTableOutput: {"name":"Chris","count":0}Example 3: Error when MR_COUNTER column is skipped and no DEFAULT clause is given
If no DEFAULT clause is specified for the MR_COUNTER column
and if the column is not skipped from the INSERT clause, an error is
thrown as shown
below.
CREATE Table myTable( name STRING,
count INTEGER AS MR_COUNTER,
PRIMARY KEY(name)) IN REGIONS DEN,LONINSERT INTO myTable VALUES ("Chris")Output:Error handling command execute 'INSERT INTO myTable VALUES ("Chris")':
Error: at (1, 0) The number of VALUES expressions is not equal to the number of table columnsYou cannot insert values into an MR_COUNTER column
explicitly. A DEFAULT construct must always be used or the
MR_COUNTER column should be skipped in the INSERT clause. If you try
to insert values into the MR_COUNTER column using the INSERT clause
or using API, an error is thrown as shown
below.
CREATE Table myTable ( name STRING,
count INTEGER AS MR_COUNTER,
PRIMARY KEY(name)) IN REGIONS DENINSERT INTO myTable VALUES("Tom",0)'Output:Error handling command execute 'INSERT INTO myTable VALUES("Tom",0)': Error: at (1, 38) MRCounter column must use DEFAULT construct.Inserting rows into a JSON column having MR_COUNTER data type:
Example: Insert data into multi-region table with a JSON MR_COUNTER
When inserting a row into the multi-region table with a JSON MR_COUNTER, you must supply a value 0 to the MR_COUNTER.
Note:
- The system initially assigns a value of 0 to all MR_COUNTER data types even if you explicitly supply a non-zero value. This also holds good when you try to provide a value that is not an INTEGER or LONG or NUMBER.
- You can't supply the keyword DEFAULT while inserting a JSON MR_COUNTER.
- The system will return an error if you try to insert data into an MR table without supplying a value to the declared JSON MR_COUNTER field or using the keyword DEFAULT.
INSERT INTO demoJSONMR VALUES ("Anna",
{
"id" : 1,
"counter" : 0,
"person" : {
"age" : 10,
"count" : 0,
"number" : 100
}
}
)SELECT * FROM demoJSONMROutput:{"name":"Anna","jsonWithCounter":{"id" : 1,"counter":0,
"person":{"age":10,"count":0,"number":100}
}
}