Though database testing is not directly possible from selenium but if you have followed selenium database testing video then you know how you can use jdbc to perform database operation from within your java selenium tests. I came across an interesting problem today when I had to insert value in a database table. On the surface corresponding database insert code looks very easy - But its execution fails on line 16 with error - ERROR: column "user_id" is of type integer but expression is of type character varying Hint: You will need to rewrite or cast the expression. Position: 163 The problem lies in the following line - queryBuilder.append("VALUES ('TRUE',?,2,'gift code [BoGJRhmTmImKJlrlFnBlZd+j2dBO3M9a]','50000','1060262','1');"); Herein user_id is represented by "?" and later replaced by real user_id in following line - updateCreditAccount.setString(1, UserMo