Add support for emitting pointer types for nullable columns

Makefile

@@ -44,7 +44,7 @@ mysqlsh:
 # $ protoc --version
 # libprotoc 3.19.1
 # $ go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
-# $ go install github.com/planetscale/vtprotobuf/cmd/protoc-gen-go-vtproto@latest
+# $ go install github.com/planetscale/vtprotobuf/cmd/protoc-gen-go-vtproto
 proto: internal/plugin/codegen.pb.go
 
 internal/plugin/codegen.pb.go: protos/plugin/codegen.proto

docs/reference/config.md

@@ -339,6 +339,7 @@ packages:
     emit_result_struct_pointers: false
     emit_params_struct_pointers: false
     emit_methods_with_db_argument: false
+    emit_pointers_for_null_types: false
     emit_enum_valid_method: false
     emit_all_enum_values: false
     json_tags_case_style: "camel"
@@ -383,6 +384,8 @@ Each mapping in the `packages` collection has the following keys:
   - If true, parameters are passed as pointers to structs. Defaults to `false`.
 - `emit_methods_with_db_argument`:
   - If true, generated methods will accept a DBTX argument instead of storing a DBTX on the `*Queries` struct. Defaults to `false`.
+- `emit_pointers_for_null_types`:
+  - If true and `sql_package` is set to `pgx/v4`, generated types for nullable columns are emitted as pointers (ie. `*string`) instead of `database/sql` null types (ie. `NullString`). Defaults to `false`.
 - `emit_enum_valid_method`:
   - If true, generate a Valid method on enum types,
     indicating whether a string is a valid enum value.

internal/cmd/shim.go

@@ -86,6 +86,7 @@ func pluginGoCode(s config.SQLGo) *plugin.GoCode {
 		EmitResultStructPointers:    s.EmitResultStructPointers,
 		EmitParamsStructPointers:    s.EmitParamsStructPointers,
 		EmitMethodsWithDbArgument:   s.EmitMethodsWithDBArgument,
+    EmitPointersForNullTypes:  s.EmitPointersForNullTypes,
 		EmitEnumValidMethod:         s.EmitEnumValidMethod,
 		EmitAllEnumValues:           s.EmitAllEnumValues,
 		JsonTagsCaseStyle:           s.JSONTagsCaseStyle,

internal/codegen/golang/postgresql_type.go

@@ -37,54 +37,79 @@ func postgresType(req *plugin.CodeGenRequest, col *plugin.Column) string {
 	columnType := sdk.DataType(col.Type)
 	notNull := col.NotNull || col.IsArray
 	driver := parseDriver(req.Settings)
+	emitPointersForNull := driver == SQLDriverPGXV4 && req.Settings.Go.EmitPointersForNullTypes
 
 	switch columnType {
 	case "serial", "serial4", "pg_catalog.serial4":
 		if notNull {
 			return "int32"
 		}
+		if emitPointersForNull {
+			return "*int32"
+		}
 		return "sql.NullInt32"
 
 	case "bigserial", "serial8", "pg_catalog.serial8":
 		if notNull {
 			return "int64"
 		}
+		if emitPointersForNull {
+			return "*int64"
+		}
 		return "sql.NullInt64"
 
 	case "smallserial", "serial2", "pg_catalog.serial2":
 		if notNull {
 			return "int16"
 		}
+		if emitPointersForNull {
+			return "*int16"
+		}
 		return "sql.NullInt16"
 
 	case "integer", "int", "int4", "pg_catalog.int4":
 		if notNull {
 			return "int32"
 		}
+		if emitPointersForNull {
+			return "*int32"
+		}
 		return "sql.NullInt32"
 
 	case "bigint", "int8", "pg_catalog.int8":
 		if notNull {
 			return "int64"
 		}
+		if emitPointersForNull {
+			return "*int64"
+		}
 		return "sql.NullInt64"
 
 	case "smallint", "int2", "pg_catalog.int2":
 		if notNull {
 			return "int16"
 		}
+		if emitPointersForNull {
+			return "*int16"
+		}
 		return "sql.NullInt16"
 
 	case "float", "double precision", "float8", "pg_catalog.float8":
 		if notNull {
 			return "float64"
 		}
+		if emitPointersForNull {
+			return "*float64"
+		}
 		return "sql.NullFloat64"
 
 	case "real", "float4", "pg_catalog.float4":
 		if notNull {
 			return "float32"
 		}
+		if emitPointersForNull {
+			return "*float32"
+		}
 		return "sql.NullFloat64" // TODO: Change to sql.NullFloat32 after updating the go.mod file
 
 	case "numeric", "pg_catalog.numeric", "money":
@@ -98,12 +123,18 @@ func postgresType(req *plugin.CodeGenRequest, col *plugin.Column) string {
 		if notNull {
 			return "string"
 		}
+		if emitPointersForNull {
+			return "*string"
+		}
 		return "sql.NullString"
 
 	case "boolean", "bool", "pg_catalog.bool":
 		if notNull {
 			return "bool"
 		}
+		if emitPointersForNull {
+			return "*bool"
+		}
 		return "sql.NullBool"
 
 	case "json":
@@ -141,30 +172,45 @@ func postgresType(req *plugin.CodeGenRequest, col *plugin.Column) string {
 		if notNull {
 			return "time.Time"
 		}
+		if emitPointersForNull {
+			return "*time.Time"
+		}
 		return "sql.NullTime"
 
 	case "pg_catalog.time", "pg_catalog.timetz":
 		if notNull {
 			return "time.Time"
 		}
+		if emitPointersForNull {
+			return "*time.Time"
+		}
 		return "sql.NullTime"
 
 	case "pg_catalog.timestamp", "pg_catalog.timestamptz", "timestamptz":
 		if notNull {
 			return "time.Time"
 		}
+		if emitPointersForNull {
+			return "*time.Time"
+		}
 		return "sql.NullTime"
 
 	case "text", "pg_catalog.varchar", "pg_catalog.bpchar", "string":
 		if notNull {
 			return "string"
 		}
+		if emitPointersForNull {
+			return "*string"
+		}
 		return "sql.NullString"
 
 	case "uuid":
 		if notNull {
 			return "uuid.UUID"
 		}
+		if emitPointersForNull {
+			return "*uuid.UUID"
+		}
 		return "uuid.NullUUID"
 
 	case "inet":
@@ -206,12 +252,18 @@ func postgresType(req *plugin.CodeGenRequest, col *plugin.Column) string {
 		if notNull {
 			return "string"
 		}
+		if emitPointersForNull {
+			return "*string"
+		}
 		return "sql.NullString"
 
 	case "interval", "pg_catalog.interval":
 		if notNull {
 			return "int64"
 		}
+		if emitPointersForNull {
+			return "*int64"
+		}
 		return "sql.NullInt64"
 
 	case "daterange":
@@ -299,6 +351,9 @@ func postgresType(req *plugin.CodeGenRequest, col *plugin.Column) string {
 					if notNull {
 						return "string"
 					}
+					if emitPointersForNull {
+						return "*string"
+					}
 					return "sql.NullString"
 				}
 			}

internal/config/config.go

@@ -119,6 +119,7 @@ type SQLGo struct {
 	EmitResultStructPointers    bool              `json:"emit_result_struct_pointers" yaml:"emit_result_struct_pointers"`
 	EmitParamsStructPointers    bool              `json:"emit_params_struct_pointers" yaml:"emit_params_struct_pointers"`
 	EmitMethodsWithDBArgument   bool              `json:"emit_methods_with_db_argument,omitempty" yaml:"emit_methods_with_db_argument"`
+  EmitPointersForNullTypes  bool              `json:"emit_pointers_for_null_types" yaml:"emit_pointers_for_null_types"`
 	EmitEnumValidMethod         bool              `json:"emit_enum_valid_method,omitempty" yaml:"emit_enum_valid_method"`
 	EmitAllEnumValues           bool              `json:"emit_all_enum_values,omitempty" yaml:"emit_all_enum_values"`
 	JSONTagsCaseStyle           string            `json:"json_tags_case_style,omitempty" yaml:"json_tags_case_style"`

internal/config/v_one.go

@@ -32,6 +32,7 @@ type v1PackageSettings struct {
 	EmitResultStructPointers  bool       `json:"emit_result_struct_pointers" yaml:"emit_result_struct_pointers"`
 	EmitParamsStructPointers  bool       `json:"emit_params_struct_pointers" yaml:"emit_params_struct_pointers"`
 	EmitMethodsWithDBArgument bool       `json:"emit_methods_with_db_argument" yaml:"emit_methods_with_db_argument"`
+	EmitPointersForNullTypes  bool       `json:"emit_pointers_for_null_types" yaml:"emit_pointers_for_null_types"`
 	EmitEnumValidMethod       bool       `json:"emit_enum_valid_method,omitempty" yaml:"emit_enum_valid_method"`
 	EmitAllEnumValues         bool       `json:"emit_all_enum_values,omitempty" yaml:"emit_all_enum_values"`
 	JSONTagsCaseStyle         string     `json:"json_tags_case_style,omitempty" yaml:"json_tags_case_style"`
@@ -130,6 +131,7 @@ func (c *V1GenerateSettings) Translate() Config {
 					EmitResultStructPointers:  pkg.EmitResultStructPointers,
 					EmitParamsStructPointers:  pkg.EmitParamsStructPointers,
 					EmitMethodsWithDBArgument: pkg.EmitMethodsWithDBArgument,
+					EmitPointersForNullTypes:  pkg.EmitPointersForNullTypes,
 					EmitEnumValidMethod:       pkg.EmitEnumValidMethod,
 					EmitAllEnumValues:         pkg.EmitAllEnumValues,
 					Package:                   pkg.Name,

internal/endtoend/testdata/emit_pointers_for_null_types/pgx/sql/character.sql

@@ -0,0 +1,17 @@
+-- Character Types
+-- https://www.postgresql.org/docs/current/datatype-character.html
+CREATE TABLE dt_character (
+    a text,
+    b character varying(32),
+    c varchar(32),
+    d character(32),
+    e char(32)
+);
+
+CREATE TABLE dt_character_not_null (
+    a text NOT NULL,
+    b character varying(32) NOT NULL,
+    c varchar(32) NOT NULL,
+    d character(32) NOT NULL,
+    e char(32) NOT NULL
+);