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DataMavn82 avatar image
DataMavn82 asked

LEFT JOIN WITH INNER JOIN

I have a query: SELECT "data" FROM t1... JOIN t2... JOIN t3... LEFT JOIN t4... JOIN t5... LEFT JOIN t6... JOIN t7(derived table)... It is my understanding that when LEFT JOINing tables, all JOINs must be LEFT JOINS or at least the final JOIN must be a LEFT JOIN. If an INNER JOIN is processed after a LEFT JOIN, it "negates" all preceding LEFT JOINs. So in the above case the LEFT JOIN on table t4 will be "negated" by the JOIN on t5 and the LEFT JOIN on t6 will be "negated" by the JOIN on t7. Am I correct?
joinsquery-resultsinner joinleft join
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IgorMicev avatar image
IgorMicev answered
No, you're wrong. Take a read for the joins for example on these sites - [ http://www.w3schools.com/sql/sql_join_left.asp][1] [1]: http://www.w3schools.com/sql/sql_join_left.asp
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