sql - REGEX check only when start of line

Question

Suppose we want to keep the entire line of a string only if a particular word say e.g 'test' appears at starting of line.

If it appears anywhere then the entire line should be removed

e.g

if function_test()=5; //here this entire line should be removed

test sample =5; //here this entire should be there

Answer 1

From Oracle 10g R2 on you should be able to use the anchor A to require the match at the beginning of the string (will only work for single-line strings thus).

http://www.regular-expressions.info/oracle.html