fix: let sqlc output nullable array

This allow postgres to output nullable array.

Co-authored-by: Conrad Hoffmann <ch@bitfehler.net>

Author: babariviere

docs/reference/config.md

@@ -14,7 +14,7 @@ sql:
   queries: "postgresql/query.sql"
   engine: "postgresql"
   gen:
-    go: 
+    go:
       package: "authors"
       out: "postgresql"
   database:
@@ -122,7 +122,7 @@ The `analyzer` mapping supports the following keys:
 
 - `database`:
   -  If false, do not use the configured database for query analysis. Defaults to `true`.
-  
+
 ### gen
 
 The `gen` mapping supports the following keys:
@@ -161,6 +161,8 @@ The `gen` mapping supports the following keys:
   - If true, generated types for nullable columns are emitted as pointers (ie. `*string`) instead of `database/sql` null types (ie. `NullString`). Currently only supported for PostgreSQL if `sql_package` is `pgx/v4` or `pgx/v5`, and for SQLite. Defaults to `false`. Nullable enum columns also follow this setting unless `emit_pointers_for_null_enum_types` is set.
 - `emit_pointers_for_null_enum_types`:
   - Overrides `emit_pointers_for_null_types` for nullable enum columns only. When `true`, nullable enum columns are emitted as pointers (ie. `*UserRole`). When `false`, nullable enum columns use the generated `NullUserRole` wrapper struct even if `emit_pointers_for_null_types` is true. Set this to `false` to keep the pre-v1.31 behavior when upgrading. Only applies to PostgreSQL with `sql_package` `pgx/v4` or `pgx/v5`.
+- `emit_nullable_for_null_arrays`:
+  - If true, generated types for nullable columns with array types are emitted as list of nullable instead of a list of non-nullable. For example, `bool[]` SQL type is emitted as `[]sql.NullBool` instead of `[]bool` when the flag is set. 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.
@@ -257,18 +259,18 @@ Each mapping in the `plugins` collection has the following keys:
     - The URL to fetch the WASM file. Supports the `https://` or `file://` schemes.
   - `sha256`
     - The SHA256 checksum for the downloaded file.
-   
+
 ```yaml
 version: "2"
 plugins:
 - name: "py"
-  wasm: 
+  wasm:
     url: "https://github.com/sqlc-dev/sqlc-gen-python/releases/download/v0.16.0-alpha/sqlc-gen-python.wasm"
     sha256: "428476c7408fd4c032da4ec74e8a7344f4fa75e0f98a5a3302f238283b9b95f2"
 - name: "js"
   env:
   - PATH
-  process: 
+  process:
     cmd: "sqlc-gen-json"
 ```
 
@@ -285,7 +287,7 @@ Each mapping in the `rules` collection has the following keys:
 
 See the [vet](../howto/vet.md) documentation for a list of built-in rules and
 help writing custom rules.
-   
+
 ```yaml
 version: "2"
 sql:
@@ -319,7 +321,7 @@ rules:
     rule: |
       query.cmd == "exec"
 ```
-  
+
 ### Global overrides
 
 Sometimes, the same configuration must be done across various specifications of

internal/codegen/golang/mysql_type.go

@@ -11,7 +11,7 @@ import (
 
 func mysqlType(req *plugin.GenerateRequest, options *opts.Options, col *plugin.Column) string {
 	columnType := sdk.DataType(col.Type)
-	notNull := col.NotNull || col.IsArray
+	notNull := col.NotNull || (col.IsArray && !options.EmitNullableForNullArrays)
 	unsigned := col.Unsigned
 
 	switch columnType {

internal/codegen/golang/opts/options.go

@@ -24,6 +24,7 @@ type Options struct {
 	EmitPointersForNullTypes  bool `json:"emit_pointers_for_null_types" yaml:"emit_pointers_for_null_types"`
 	// nil inherits EmitPointersForNullTypes; non-nil overrides for enums only.
 	EmitPointersForNullEnumTypes *bool             `json:"emit_pointers_for_null_enum_types,omitempty" yaml:"emit_pointers_for_null_enum_types"`
+	EmitNullableForNullArrays    bool              `json:"emit_nullable_for_null_arrays" yaml:"emit_nullable_for_null_arrays"`
 	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"`
 	EmitSqlAsComment             bool              `json:"emit_sql_as_comment,omitempty" yaml:"emit_sql_as_comment"`

internal/codegen/golang/postgresql_type.go

@@ -36,7 +36,7 @@ func parseIdentifierString(name string) (*plugin.Identifier, error) {
 
 func postgresType(req *plugin.GenerateRequest, options *opts.Options, col *plugin.Column) string {
 	columnType := sdk.DataType(col.Type)
-	notNull := col.NotNull || col.IsArray
+	notNull := col.NotNull || (col.IsArray && !options.EmitNullableForNullArrays)
 	driver := parseDriver(options.SqlPackage)
 	emitPointersForNull := driver.IsPGX() && options.EmitPointersForNullTypes
 	emitPointersForNullEnums := emitPointersForNull

internal/codegen/golang/sqlite_type.go

@@ -12,7 +12,7 @@ import (
 
 func sqliteType(req *plugin.GenerateRequest, options *opts.Options, col *plugin.Column) string {
 	dt := strings.ToLower(sdk.DataType(col.Type))
-	notNull := col.NotNull || col.IsArray
+	notNull := col.NotNull || (col.IsArray && !options.EmitNullableForNullArrays)
 	emitPointersForNull := options.EmitPointersForNullTypes
 
 	switch dt {

internal/config/v_one.go

@@ -40,6 +40,7 @@ type v1PackageSettings struct {
 	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"`
 	EmitPointersForNullEnumTypes *bool             `json:"emit_pointers_for_null_enum_types,omitempty" yaml:"emit_pointers_for_null_enum_types"`
+	EmitNullableForNullArrays    bool              `json:"emit_nullable_for_null_arrays" yaml:"emit_nullable_for_null_arrays"`
 	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"`
 	EmitSqlAsComment             bool              `json:"emit_sql_as_comment,omitempty" yaml:"emit_sql_as_comment"`
@@ -155,6 +156,7 @@ func (c *V1GenerateSettings) Translate() Config {
 					EmitMethodsWithDbArgument:    pkg.EmitMethodsWithDBArgument,
 					EmitPointersForNullTypes:     pkg.EmitPointersForNullTypes,
 					EmitPointersForNullEnumTypes: pkg.EmitPointersForNullEnumTypes,
+					EmitNullableForNullArrays:    pkg.EmitNullableForNullArrays,
 					EmitEnumValidMethod:          pkg.EmitEnumValidMethod,
 					EmitAllEnumValues:            pkg.EmitAllEnumValues,
 					EmitSqlAsComment:             pkg.EmitSqlAsComment,