sqlcmp is a Go package designed to facilitate the comparison of SQL queries by parsing them into tokens and allowing for the comparison of these tokens in parts. This functionality is particularly useful for applications that need to determine if two SQL queries are semantically equivalent, ignoring differences in formatting, whitespace, or the order of clauses.
The package provides a function SemiHash that takes a SQL query and a mask specifying which parts of the query to consider for comparison. The mask can include segments such as WHERE, FROM, and SkipValues, which allows for a flexible comparison of queries. For example, two queries with the same WHERE and FROM clauses but in different orders, or with different values in the WHERE clause, can be considered equivalent if the mask is set to compare these segments.
Comparing two SQL queries by FROM and WHERE sections:
import (
"fmt"
"github.com/vench/sqlcmp"
)
var (
query1 = "SELECT * FROM phones WHERE date > '2023-09-27' AND user_id = 1004;"
query2 = "SELECT * FROM phones WHERE user_id = 1004 AND date > '2023-09-27';"
mask = sqlcmp.SegmentWhere|sqlcmp.SegmentFrom|sqlcmp.SegmentSkipValues
)
hash1, _ := sqlcmp.SemiHash(query1, mask)
hash2, _ := sqlcmp.SemiHash(query2, mask)
fmt.Println(hash1 == hash2) // print trueYou can find more examples in the directory examples.