Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.
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The SELECT line will raise a error message:
create table tbl_EE_1 ( pk int , data varchar(10) ) create table tbl_EE_2 ( pk int, fk int, data varchar(10) ) go select * from tbl_EE_1 join tbl_EE_2 on fk = pk go drop table tbl_EE_1 drop table tbl_EE_2
select * from tbl_EE_1 join tbl_EE_2 on fk = tbl_EE_1.pk
The big advantage of this is that queries written like that will not break with the error mentionned above, even if later on, a new column "fk" would be added to tbl_EE_1, which would make the "fk" reference ambiguous.
select * from tbl_EE_1 join tbl_EE_2 on table_EE_2.fk = tbl_EE_1.pk
This will be efficient and safe, but as you can see, long-winded for writing the sql, as you have to prefix for each column that full table name.
select tbl_EE_1.pk AS pk1, tbl_EE_1.data AS data1, tbl_EE_2.data AS data2 from tbl_EE_1 join tbl_EE_2 on table_EE_2.fk = tbl_EE_1.pk
As you can see, even if slightly longer than the original query code, it will be safe, very easy to read.
select t1.pk AS pk1, t1.data AS data1, t2.data AS data2 from tbl_EE_1 t1 join tbl_EE_2 t2 on t2.fk = t1.pk
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