Querying the inner join of two tables with the same column name, Column 'exName' in field list is ambiguous

Question

I am querying the inner join of three tables using the following query.

Two of the tables have columns named "name1". I am getting the following error.

Column 'exName' in field list is ambiguous

The "name1" columns are foreign key so the information should be identical. Can anyone suggest a compact way around this?

$result = mysql_query("SELECT name1,name2,name3 FROM `table1` INNER JOIN `table2` ON table2.name1=table1.PrimaryKey INNER JOIN `table3` ON table3.name1=table1.PrimaryKey"); 

Answer 1

You need to qualify your column names with the table names.

 SELECT table1.name1, table2.name1, etc.

Answer 2

You need to refer to the columns in your select list as:

SELECT <table name>.name1, <table name>.name2, <table name>.name3

You can also give the tables an alias when you introduce them in the from clause to save some keystrokes and make things cleaner:

SELECT 
     t1.name1
    ,t2.name2
    ,t3.name3
FROM table1 AS t1
INNER JOIN table2 AS t2
    ON t2.name1 = t1.PrimaryKey
INNER JOIN table3 AS t3
    ON t3.name1 = t1.PrimaryKey