mysql fulltext - exact match or nothing
PROPOSED QUERY

SELECT * FROM test WHERE MATCH(tags)
AGAINST ('"+proj_7" "(invoice report)"' IN BOOLEAN MODE);


YOUR SAMPLE DATA LOADED

mysql&gt; USE test
Database changed
mysql&gt; DROP TABLE IF EXISTS test;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql&gt; CREATE TABLE `test` (
    -&gt;   `tags` text NOT NULL,
    -&gt;   FULLTEXT KEY `tags` (`tags`)
    -&gt; );
Query OK, 0 rows affected (0.20 sec)

mysql&gt; INSERT INTO test (tags) VALUES ("proj_7 type_invdtl year_15 month_04");
Query OK, 1 row affected (0.00 sec)

mysql&gt; INSERT INTO test (tags) VALUES ("proj_8 type_invdtl year_15 month_04");
Query OK, 1 row affected (0.00 sec)

mysql&gt; INSERT INTO test (tags) VALUES ("proj_10 type_invdtl year_15 month_04");
Query OK, 1 row affected (0.02 sec)

mysql&gt; SELECT * FROM test;
+--------------------------------------+
| tags                                 |
+--------------------------------------+
| proj_7 type_invdtl year_15 month_04  |
| proj_8 type_invdtl year_15 month_04  |
| proj_10 type_invdtl year_15 month_04 |
+--------------------------------------+
3 rows in set (0.00 sec)

mysql&gt;


PROPOSED QUERY EXECUTED

mysql&gt; SELECT * FROM test WHERE MATCH(tags)
    -&gt; AGAINST ('"+proj_7" "(invoice report)"' IN BOOLEAN MODE);
+-------------------------------------+
| tags                                |
+-------------------------------------+
| proj_7 type_invdtl year_15 month_04 |
+-------------------------------------+
1 row in set (0.00 sec)

mysql&gt;


OTHER EXAMPLES

mysql&gt; SELECT * FROM test WHERE MATCH(tags)
    -&gt; AGAINST ('"+proj_7" "(type_invdtl year_15)"' IN BOOLEAN MODE);
+--------------------------------------+
| tags                                 |
+--------------------------------------+
| proj_7 type_invdtl year_15 month_04  |
| proj_8 type_invdtl year_15 month_04  |
| proj_10 type_invdtl year_15 month_04 |
+--------------------------------------+
3 rows in set (0.00 sec)

mysql&gt; SELECT * FROM test WHERE MATCH(tags)
    -&gt; AGAINST ('"+proj_7" "(type_invdt2 year_15)"' IN BOOLEAN MODE);
+-------------------------------------+
| tags                                |
+-------------------------------------+
| proj_7 type_invdtl year_15 month_04 |
+-------------------------------------+
1 row in set (0.00 sec)

mysql&gt; SELECT * FROM test WHERE MATCH(tags) AGAINST ('"+proj_7 +type_invdtl" "+proj_7 +year15"' IN BOOLEAN MODE);
+-------------------------------------+
| tags                                |
+-------------------------------------+
| proj_7 type_invdtl year_15 month_04 |
+-------------------------------------+
1 row in set (0.00 sec)

mysql&gt; SELECT * FROM test WHERE MATCH(tags) AGAINST ('"+proj_7 +type_invdtl" "+proj_7 +year16"' IN BOOLEAN MODE);
+-------------------------------------+
| tags                                |
+-------------------------------------+
| proj_7 type_invdtl year_15 month_04 |
+-------------------------------------+
1 row in set (0.00 sec)

mysql&gt; SELECT * FROM test WHERE MATCH(tags) AGAINST ('"+proj_7 +type_invdt2" "+proj_7 +year16"' IN BOOLEAN MODE);
Empty set (0.00 sec)

mysql&gt;


GIVE IT A TRY !!!