internal/dinosql: Use more database/sql null types

internal/dinosql/gen.go

@@ -490,25 +490,31 @@ func (r Result) goInnerType(col core.Column) string {
 
 	switch columnType {
 	case "serial", "pg_catalog.serial4":
-		return "int32"
+		if notNull {
+			return "int32"
+		}
+		return "sql.NullInt32"
 
 	case "bigserial", "pg_catalog.serial8":
 		if notNull {
 			return "int64"
 		}
-		return "sql.NullInt64" // unnecessay else
+		return "sql.NullInt64"
 
 	case "smallserial", "pg_catalog.serial2":
 		return "int16"
 
 	case "integer", "int", "pg_catalog.int4":
-		return "int32"
+		if notNull {
+			return "int32"
+		}
+		return "sql.NullInt32"
 
 	case "bigint", "pg_catalog.int8":
 		if notNull {
 			return "int64"
 		}
-		return "sql.NullInt64" // unnecessary else
+		return "sql.NullInt64"
 
 	case "smallint", "pg_catalog.int2":
 		return "int16"
@@ -517,19 +523,19 @@ func (r Result) goInnerType(col core.Column) string {
 		if notNull {
 			return "float64"
 		}
-		return "sql.NullFloat64" // unnecessary else
+		return "sql.NullFloat64"
 
 	case "real", "pg_catalog.float4":
 		if notNull {
 			return "float32"
-		} // unnecessary else
-		return "sql.NullFloat64" // IMPORTANT: Change to sql.NullFloat32 after updating the go.mod file
+		}
+		return "sql.NullFloat64" // TODO: Change to sql.NullFloat32 after updating the go.mod file
 
 	case "bool", "pg_catalog.bool":
 		if notNull {
 			return "bool"
 		}
-		return "sql.NullBool" // unnecessary else
+		return "sql.NullBool"
 
 	case "jsonb":
 		return "json.RawMessage"
@@ -541,13 +547,13 @@ func (r Result) goInnerType(col core.Column) string {
 		if notNull {
 			return "time.Time"
 		}
-		return "pq.NullTime" // unnecessary else
+		return "sql.NullTime"
 
 	case "text", "pg_catalog.varchar", "pg_catalog.bpchar":
 		if notNull {
 			return "string"
 		}
-		return "sql.NullString" // unnecessary else
+		return "sql.NullString"
 
 	case "uuid":
 		return "uuid.UUID"

internal/dinosql/gen_test.go

@@ -78,19 +78,39 @@ func TestColumnsToStruct(t *testing.T) {
 
 func TestInnerType(t *testing.T) {
 	r := Result{}
-	for _, tc := range []struct {
-		col      pg.Column
-		expected string
-	}{
-		{
-			pg.Column{Name: "created", DataType: "timestamptz", NotNull: true},
-			"time.Time",
-		},
-	} {
-		tt := tc
-		t.Run(tt.col.Name+"-"+tt.col.DataType, func(t *testing.T) {
-			if diff := cmp.Diff(tt.expected, r.goType(tt.col)); diff != "" {
-				t.Errorf("struct mismatch: \n%s", diff)
+	types := map[string]string{
+		"timestamptz":     "time.Time",
+		"integer":         "int32",
+		"int":             "int32",
+		"pg_catalog.int4": "int32",
+	}
+	for k, v := range types {
+		dbType := k
+		goType := v
+		t.Run(k+"-"+v, func(t *testing.T) {
+			col := pg.Column{DataType: dbType, NotNull: true}
+			if goType != r.goType(col) {
+				t.Errorf("expected Go type for %s to be %s, not %s", dbType, goType, r.goType(col))
+			}
+		})
+	}
+}
+
+func TestNullInnerType(t *testing.T) {
+	r := Result{}
+	types := map[string]string{
+		"timestamptz":     "sql.NullTime",
+		"integer":         "sql.NullInt32",
+		"int":             "sql.NullInt32",
+		"pg_catalog.int4": "sql.NullInt32",
+	}
+	for k, v := range types {
+		dbType := k
+		goType := v
+		t.Run(k+"-"+v, func(t *testing.T) {
+			col := pg.Column{DataType: dbType, NotNull: false}
+			if goType != r.goType(col) {
+				t.Errorf("expected Go type for %s to be %s, not %s", dbType, goType, r.goType(col))
 			}
 		})
 	}