@LJinJC
You have not mentioned the criteria for your data. What is it from the SQL that you are trying to display as a default?
You need to basically do a LookUp on the SQL connection to get the value you want.
Example, in the Default property of your TextInput control:
LookUp(yourSQLTable, <criteria>, <column>)
Where criteria specifies what record to look up, and column specifies the column of your table that you want the data from.
I hope this is helpful for you.