数据库命名的正则表达式

Question

I've thousand of queries I need to execute from a text file.

See bellow a kind of query I have:

SELECT * 
    FROM T1 A 
    INNER JOIN DB2.dbo.CI_T1 B ON A.id= B.id 
    LEFT OUTER JOIN T3 C ON B.id = C.id
    WHERE ...

Some of tables are well named (database.owner.table_name), and some other no (table_name).

How can I use a regex to update each query to replace unqualified instances of table_name with database.owner.table_name?

I write fiddle to test it: http://www.phpliveregex.com/p/9SH and http://www.phpliveregex.com/p/9SF

Answer 1

In the end I use following regex with preg_replace function:

$regex = '#(FROM)\s+((?!\.)[[:alnum:]_]+)\s+(\w*)\s*(INNER|LEFT|WHERE|\))#i';
$regex2 = '#(JOIN)\s+((?!\.)[[:alnum:]_]+)\s+(\w*)\s*(ON)#i';