I've been working with GridDB and exploring its capabilities concerning data management and retrieval. I recently encountered an unexpected behavior when attempting to convert a STRING type to a TIMESTAMP type using the provided TQL commands.
I have a container with a schema where one of the columns is defined as STRING. I've been storing date-time values in this STRING column in the format 'YYYY-MM-DD HH:MM:SS'. I decided to convert this STRING column to a TIMESTAMP column to use the time-series functionalities of GridDB better. I used the following TQL command to alter the container schema:
ALTER TABLE my_container ALTER COLUMN date_column TYPE TIMESTAMP;
After executing the above command, I noticed that the date-time values stored in the date_column were not correctly converted to TIMESTAMP values. Instead, they seemed to be interpreted as integer values, which resulted in incorrect TIMESTAMP values.
I referred to the GridDB TQL reference but could not find a detailed explanation on data type conversions, specifically from STRING to TIMESTAMP.
My question is;
Is there a specific TQL command or function that should be used to correctly convert STRING values to TIMESTAMP values in GridDB?