fix: let sqlc output nullable array

Close #1851

This allow postgres to output nullable array.

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:
@@ -159,6 +159,8 @@ The `gen` mapping supports the following keys:
   - 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, 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`.
+- `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.
@@ -255,18 +257,18 @@ 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"
 ```
 
@@ -283,7 +285,7 @@ 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:
@@ -317,7 +319,7 @@ rules:
     rule: |
       query.cmd == "exec"
 ```
-  
+
 ### Global overrides
 
 Sometimes, the same configuration must be done across various specifications of

internal/codegen/golang/opts/options.go

@@ -22,6 +22,7 @@ type Options struct {
 	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"`
+	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
 

internal/config/v_one.go

@@ -39,6 +39,7 @@ type v1PackageSettings struct {
 	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"`
+	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"`
@@ -149,6 +150,7 @@ func (c *V1GenerateSettings) Translate() Config {
 					EmitParamsStructPointers:  pkg.EmitParamsStructPointers,
 					EmitMethodsWithDbArgument: pkg.EmitMethodsWithDBArgument,
 					EmitPointersForNullTypes:  pkg.EmitPointersForNullTypes,
+					EmitNullableForNullArrays: pkg.EmitNullableForNullArrays,
 					EmitEnumValidMethod:       pkg.EmitEnumValidMethod,
 					EmitAllEnumValues:         pkg.EmitAllEnumValues,
 					EmitSqlAsComment:          pkg.EmitSqlAsComment,

internal/endtoend/testdata/unnest_null/postgresql/pgx/v4/go/db.go

@@ -0,0 +1,9 @@
+-- name: CreateMemories :many
+INSERT INTO memories (vampire_id)
+SELECT
+    unnest(sqlc.narg(vamprie_id)::uuid[]) AS vampire_id
+RETURNING
+    *;
+
+-- name: GetVampireIDs :many
+SELECT vampires.id::uuid FROM unnest(sqlc.narg(vampire_id)::uuid[]) AS vampires (id);

internal/endtoend/testdata/unnest_null/postgresql/pgx/v4/go/models.go

@@ -0,0 +1,10 @@
+CREATE TABLE vampires (
+    id uuid PRIMARY KEY DEFAULT gen_random_uuid ()
+);
+
+CREATE TABLE memories (
+    id uuid PRIMARY KEY DEFAULT gen_random_uuid (),
+    vampire_id uuid REFERENCES vampires (id),
+    created_at timestamp NOT NULL DEFAULT NOW(),
+    updated_at timestamp
+);