Guess by similar table/column names

Author: syucream

Gopkg.lock

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	_ "github.com/go-sql-driver/mysql"
+	"github.com/syucream/hakagi/src/constraint"
 	"github.com/syucream/hakagi/src/database"
 	"github.com/syucream/hakagi/src/formatter"
 	"github.com/syucream/hakagi/src/guess"
@@ -37,7 +38,9 @@ func main() {
 		log.Fatalf("Failed to fetch primary keys : %v", err)
 	}
 
-	constraints := guess.GuessByPrimaryKeyName(schemas, primaryKeys)
+	var constraints []constraint.Constraint
+	constraints = append(constraints, guess.GuessByPrimaryKeyName(schemas, primaryKeys)...)
+	constraints = append(constraints, guess.GuessBySimilarColumn(schemas)...)
 
 	alterQuery := formatter.FormatSql(constraints)
 	fmt.Println(alterQuery)

cmd/hakagi/hakagi.go

@@ -1,11 +1,13 @@
 package guess
 
 import (
+	"github.com/jinzhu/inflection"
 	"github.com/syucream/hakagi/src/constraint"
 	"github.com/syucream/hakagi/src/database"
 )
 
 const (
+	idColumn               = "id"
 	targetPrimaryKeySuffix = "_id"
 )
 
@@ -15,6 +17,11 @@ func isTargetPrimaryKey(column string) bool {
 	return cLen >= tLen && column[cLen-tLen:] == targetPrimaryKeySuffix
 }
 
+func isSimilarColumn(left, right database.Schema) bool {
+	maybeRightTable := inflection.Plural(left.Column)
+	return maybeRightTable == right.Table && right.Column == idColumn
+}
+
 // Recongnize a column thats same name of other table's primary key is a foreign key
 // This base idea refers to SchemaSpy DbAnalyzer:
 //   https://github.com/schemaspy/schemaspy/blob/master/src/main/java/org/schemaspy/DbAnalyzer.java
@@ -31,3 +38,17 @@ func GuessByPrimaryKeyName(schemas []database.Schema, primaryKeys []database.Pri
 
 	return constraints
 }
+
+func GuessBySimilarColumn(schemas []database.Schema) []constraint.Constraint {
+	var constraints []constraint.Constraint
+
+	for _, left := range schemas {
+		for _, right := range schemas {
+			if left.Table != right.Table && isSimilarColumn(left, right) {
+				constraints = append(constraints, constraint.Constraint{left.Table, left.Column, right.Table, right.Column})
+			}
+		}
+	}
+
+	return constraints
+}