Create table with a REGEXP_LIKE Constraint

CREATE TABLE regexp_temp(Name varchar2(20), emailID varchar2(20) CONSTRAINT mailchck CHECK (REGEXP_LIKE (emailID, '^(\S+)\@(\S+)\.(\S+)$')))

Insert a valid row

INSERT INTO regexp_temp (Name, emailID) VALUES ('abcd', 'abcd@email.com')

Select the inserted information for display

SELECT emailID FROM regexp_temp WHERE REGEXP_LIKE(emailID, '^(\S+)\@(\S+)\.(\S+)$')

DROP TABLE regexp_temp

Create a table without a constraint clause

CREATE TABLE regexp_temp(Name varchar2(20), emailID varchar2(20))

INSERT INTO regexp_temp (Name, emailID) VALUES ('efgh', 'efghemail.com')

INSERT INTO regexp_temp (Name, emailID) VALUES ('ijkl', 'efghijkl.com')

INSERT INTO regexp_temp (Name, emailID) VALUES ('mnop', 'mnop@email.com')

INSERT INTO regexp_temp (Name, emailID) VALUES ('wxyz', 'wxyz@email.com')

Querty the table with REGEXP_LIKE

SELECT emailID "VALID EMAILS" FROM regexp_temp WHERE REGEXP_LIKE(emailID, '^(\S+)\@(\S+)\.(\S+)$')

Query the table for non-matching email IDs

SELECT emailID "INVALID EMAILS" FROM regexp_temp WHERE emailID NOT LIKE '%_@_%'

DROP TABLE regexp_temp