Support for using TEXT as a foreign key target

go.mod

@@ -10,7 +10,7 @@ require (
 	github.com/dolthub/dolt/go/gen/proto/dolt/services/eventsapi v0.0.0-20241119094239-f4e529af734d
 	github.com/dolthub/flatbuffers/v23 v23.3.3-dh.2
 	github.com/dolthub/go-icu-regex v0.0.0-20250303123116-549b8d7cad00
-	github.com/dolthub/go-mysql-server v0.19.1-0.20250306014046-f73a318f7731
+	github.com/dolthub/go-mysql-server v0.19.1-0.20250307161823-e8ce0df0d8f2
 	github.com/dolthub/sqllogictest/go v0.0.0-20240618184124-ca47f9354216
 	github.com/dolthub/vitess v0.0.0-20250304211657-920ca9ec2b9a
 	github.com/fatih/color v1.13.0

go.sum

@@ -224,8 +224,8 @@ github.com/dolthub/fslock v0.0.3 h1:iLMpUIvJKMKm92+N1fmHVdxJP5NdyDK5bK7z7Ba2s2U=
 github.com/dolthub/fslock v0.0.3/go.mod h1:QWql+P17oAAMLnL4HGB5tiovtDuAjdDTPbuqx7bYfa0=
 github.com/dolthub/go-icu-regex v0.0.0-20250303123116-549b8d7cad00 h1:rh2ij2yTYKJWlX+c8XRg4H5OzqPewbU1lPK8pcfVmx8=
 github.com/dolthub/go-icu-regex v0.0.0-20250303123116-549b8d7cad00/go.mod h1:ylU4XjUpsMcvl/BKeRRMXSH7e7WBrPXdSLvnRJYrxEA=
-github.com/dolthub/go-mysql-server v0.19.1-0.20250306014046-f73a318f7731 h1:flDUXUqKRo4u5gdoQZBeO3jESUnCNkv01GDmiZbgAA4=
-github.com/dolthub/go-mysql-server v0.19.1-0.20250306014046-f73a318f7731/go.mod h1:yr+Vv47/YLOKMgiEY+QxHTlbIVpTuiVtkEZ5l+xruY4=
+github.com/dolthub/go-mysql-server v0.19.1-0.20250307161823-e8ce0df0d8f2 h1:5AAJTJWaiYO1ut8TkEKbeBTp3x0UIOd1yV9nC1s3vjg=
+github.com/dolthub/go-mysql-server v0.19.1-0.20250307161823-e8ce0df0d8f2/go.mod h1:yr+Vv47/YLOKMgiEY+QxHTlbIVpTuiVtkEZ5l+xruY4=
 github.com/dolthub/gozstd v0.0.0-20240423170813-23a2903bca63 h1:OAsXLAPL4du6tfbBgK0xXHZkOlos63RdKYS3Sgw/dfI=
 github.com/dolthub/gozstd v0.0.0-20240423170813-23a2903bca63/go.mod h1:lV7lUeuDhH5thVGDCKXbatwKy2KW80L4rMT46n+Y2/Q=
 github.com/dolthub/ishell v0.0.0-20240701202509-2b217167d718 h1:lT7hE5k+0nkBdj/1UOSFwjWpNxf+LCApbRHgnCA17XE=

server/analyzer/init.go

@@ -15,7 +15,12 @@
 package analyzer
 
 import (
+	"strings"
+
+	"github.com/dolthub/go-mysql-server/sql"
 	"github.com/dolthub/go-mysql-server/sql/analyzer"
+	"github.com/dolthub/go-mysql-server/sql/plan"
+	"github.com/dolthub/vitess/go/sqltypes"
 )
 
 // IDs are basically arbitrary, we just need to ensure that they do not conflict with existing IDs
@@ -86,6 +91,49 @@ func Init() {
 		analyzer.Rule{Id: ruleId_AddDomainConstraintsToCasts, Apply: AddDomainConstraintsToCasts},
 		analyzer.Rule{Id: ruleId_ReplaceNode, Apply: ReplaceNode},
 		analyzer.Rule{Id: ruleId_InsertContextRootFinalizer, Apply: InsertContextRootFinalizer})
+
+	initEngine()
+}
+
+func initEngine() {
+	plan.ValidateForeignKeyDefinition = validateForeignKeyDefinition
+}
+
+// validateForeignKeyDefinition validates that the given foreign key definition is valid for creation
+func validateForeignKeyDefinition(ctx *sql.Context, fkDef sql.ForeignKeyConstraint, cols map[string]*sql.Column, parentCols map[string]*sql.Column) error {
+	// TODO: this check is too permissive, we should be doing some type checks here
+	for i := range fkDef.Columns {
+		col := cols[strings.ToLower(fkDef.Columns[i])]
+		parentCol := parentCols[strings.ToLower(fkDef.ParentColumns[i])]
+		if !foreignKeyComparableTypes(ctx, col.Type, parentCol.Type) {
+			return sql.ErrForeignKeyColumnTypeMismatch.New(fkDef.Columns[i], fkDef.ParentColumns[i])
+		}
+	}
+	return nil
+}
+
+// foreignKeyComparableTypes returns whether the two given types are able to be used as parent/child columns in a
+// foreign key.
+func foreignKeyComparableTypes(ctx *sql.Context, type1 sql.Type, type2 sql.Type) bool {
+	if !type1.Equals(type2) {
+		// There seems to be a special case where CHAR/VARCHAR/BINARY/VARBINARY can have unequal lengths.
+		// Have not tested every type nor combination, but this seems specific to those 4 types.
+		if type1.Type() == type2.Type() {
+			switch type1.Type() {
+			case sqltypes.Char, sqltypes.VarChar, sqltypes.Binary, sqltypes.VarBinary:
+				type1String := type1.(sql.StringType)
+				type2String := type2.(sql.StringType)
+				if type1String.Collation().CharacterSet() != type2String.Collation().CharacterSet() {
+					return false
+				}
+			default:
+				return false
+			}
+		} else {
+			return false
+		}
+	}
+	return true
 }
 
 // insertAnalyzerRules inserts the given rule(s) before or after the given analyzer.RuleId, returning an updated slice.

testing/go/foreign_keys_test.go

@@ -44,6 +44,26 @@ func TestForeignKeys(t *testing.T) {
 					},
 				},
 			},
+			{
+				Name: "text foreign key",
+				SetUpScript: []string{
+					`CREATE TABLE parent (a text PRIMARY KEY, b int)`,
+					`CREATE TABLE child (a INT PRIMARY KEY, b text, FOREIGN KEY (b) REFERENCES parent(a))`,
+					`INSERT INTO parent VALUES ('a', 1)`,
+				},
+				Assertions: []ScriptTestAssertion{
+					{
+						Query: "INSERT INTO child VALUES (1, 'a')",
+					},
+					{
+						Query: "INSERT INTO child VALUES (2, 'a')",
+					},
+					{
+						Query:       "INSERT INTO child VALUES (3, 'b')",
+						ExpectedErr: "Foreign key violation",
+					},
+				},
+			},
 			{
 				Name: "foreign key with dolt_add, dolt_commit",
 				SetUpScript: []string{