Add MySQL support (#230)

With this commit, sqlc now supports two database engines: PostgreSQL and MySQL. The MySQL support contained in this change is experimental. It still fails to parse many valid queries, and the code generated for some queries is incorrect.

Also, the interface between parsing, codegen, and database catalog is a bit of a mess. The goal of merging this support in now is to make progress towards 1.0

Co-authored-by: Charles Moog <moogcharlie@gmail.com>

Author: kyleconroy

README.md

@@ -307,6 +307,8 @@ Each package document has the following keys:
   - Directory of SQL queries or path to single SQL file
 - `schema`:
   - Directory of SQL migrations or path to single SQL file
+- `engine`:
+  - Either `postgresql` or `mysql`. Defaults to `postgresql`. MySQL support is experimental
 
 ### Type Overrides
 
@@ -411,13 +413,17 @@ Each commit is deployed to the [`devel` channel on Equinox](https://dl.equinox.i
 - [Linux](https://bin.equinox.io/c/gvM95th6ps1/sqlc-devel-linux-amd64.tgz)
 - [macOS](https://bin.equinox.io/c/gvM95th6ps1/sqlc-devel-darwin-amd64.zip)
 
-## Other Database Engines
+## Other Databases and Languages
 
-sqlc currently only supports PostgreSQL. If you'd like to support another database, we'd welcome a contribution.
+sqlc currently only supports PostgreSQL / Go. MySQL support has been merged,
+but it's marked as experimental. SQLite and TypeScript support are planned.
 
-## Other Language Backends
+| Language     | PostgreSQL       | MySQL            | SQLite           |
+| ------------ |:----------------:|:----------------:|:----------------:|
+| Go           |:white_check_mark:|:warning:         |:timer_clock:     |
+| TypeScript   |:timer_clock:     |:timer_clock:     |:timer_clock:     |
 
-sqlc currently only generates Go code, but if you'd like to build another language backend, we'd welcome a contribution.
+If you'd like to add another database or language, we'd welcome a contribution.
 
 ## Acknowledgements
 

go.mod

@@ -8,4 +8,10 @@ require (
 	github.com/jinzhu/inflection v1.0.0
 	github.com/lfittl/pg_query_go v1.0.0
 	github.com/spf13/cobra v0.0.5
+	github.com/spf13/pflag v1.0.5 // indirect
+	golang.org/x/net v0.0.0-20191209160850-c0dbc17a3553 // indirect
+	golang.org/x/sys v0.0.0-20191220220014-0732a990476f // indirect
+	google.golang.org/genproto v0.0.0-20191223191004-3caeed10a8bf // indirect
+	google.golang.org/grpc v1.26.0 // indirect
+	vitess.io/vitess v0.0.0-20191113025808-0629f0da20ab
 )

go.sum

@@ -11,6 +11,7 @@ import (
 	"path/filepath"
 
 	"github.com/kyleconroy/sqlc/internal/dinosql"
+	"github.com/kyleconroy/sqlc/internal/mysql"
 
 	"github.com/davecgh/go-spew/spew"
 	pg "github.com/lfittl/pg_query_go"
@@ -126,48 +127,57 @@ var genCmd = &cobra.Command{
 
 		output := map[string]string{}
 
-		for i, pkg := range settings.Packages {
+		for _, pkg := range settings.Packages {
 			name := pkg.Name
 
-			if pkg.Path == "" {
-				fmt.Fprintf(os.Stderr, "package[%d]: path must be set\n", i)
-				errored = true
-				continue
-			}
+			var result dinosql.Generateable
 
-			if name == "" {
-				name = filepath.Base(pkg.Path)
-			}
+			switch pkg.Engine {
 
-			c, err := dinosql.ParseCatalog(pkg.Schema)
-			if err != nil {
-				fmt.Fprintf(os.Stderr, "# package %s\n", name)
-				if parserErr, ok := err.(*dinosql.ParserErr); ok {
-					for _, fileErr := range parserErr.Errs {
-						fmt.Fprintf(os.Stderr, "%s:%d:%d: %s\n", fileErr.Filename, fileErr.Line, fileErr.Column, fileErr.Err)
+			case dinosql.EngineMySQL:
+				// Experimental MySQL support
+				q, err := mysql.GeneratePkg(name, pkg.Schema, pkg.Queries, settings)
+				if err != nil {
+					fmt.Fprintf(os.Stderr, "# package %s\n", name)
+					fmt.Fprintf(os.Stderr, "error parsing file: %s\n", err)
+					errored = true
+					continue
+				}
+				result = q
+
+			case dinosql.EnginePostgreSQL:
+				c, err := dinosql.ParseCatalog(pkg.Schema)
+				if err != nil {
+					fmt.Fprintf(os.Stderr, "# package %s\n", name)
+					if parserErr, ok := err.(*dinosql.ParserErr); ok {
+						for _, fileErr := range parserErr.Errs {
+							fmt.Fprintf(os.Stderr, "%s:%d:%d: %s\n", fileErr.Filename, fileErr.Line, fileErr.Column, fileErr.Err)
+						}
+					} else {
+						fmt.Fprintf(os.Stderr, "error parsing schema: %s\n", err)
 					}
-				} else {
-					fmt.Fprintf(os.Stderr, "error parsing schema: %s\n", err)
+					errored = true
+					continue
 				}
-				errored = true
-				continue
-			}
 
-			q, err := dinosql.ParseQueries(c, settings, pkg)
-			if err != nil {
-				fmt.Fprintf(os.Stderr, "# package %s\n", name)
-				if parserErr, ok := err.(*dinosql.ParserErr); ok {
-					for _, fileErr := range parserErr.Errs {
-						fmt.Fprintf(os.Stderr, "%s:%d:%d: %s\n", fileErr.Filename, fileErr.Line, fileErr.Column, fileErr.Err)
+				q, err := dinosql.ParseQueries(c, pkg)
+				if err != nil {
+					fmt.Fprintf(os.Stderr, "# package %s\n", name)
+					if parserErr, ok := err.(*dinosql.ParserErr); ok {
+						for _, fileErr := range parserErr.Errs {
+							fmt.Fprintf(os.Stderr, "%s:%d:%d: %s\n", fileErr.Filename, fileErr.Line, fileErr.Column, fileErr.Err)
+						}
+					} else {
+						fmt.Fprintf(os.Stderr, "error parsing queries: %s\n", err)
 					}
-				} else {
-					fmt.Fprintf(os.Stderr, "error parsing queries: %s\n", err)
+					errored = true
+					continue
 				}
-				errored = true
-				continue
+				result = q
+
 			}
 
-			files, err := dinosql.Generate(q, settings, pkg)
+			files, err := dinosql.Generate(result, settings)
 			if err != nil {
 				fmt.Fprintf(os.Stderr, "# package %s\n", name)
 				fmt.Fprintf(os.Stderr, "error generating code: %s\n", err)
@@ -199,13 +209,13 @@ var checkCmd = &cobra.Command{
 	Use:   "compile",
 	Short: "Statically check SQL for syntax and type errors",
 	RunE: func(cmd *cobra.Command, args []string) error {
-		blob, err := ioutil.ReadFile("sqlc.json")
+		file, err := os.Open("sqlc.json")
 		if err != nil {
 			return err
 		}
 
-		var settings dinosql.GenerateSettings
-		if err := json.Unmarshal(blob, &settings); err != nil {
+		settings, err := dinosql.ParseConfig(file)
+		if err != nil {
 			return err
 		}
 
@@ -214,7 +224,7 @@ var checkCmd = &cobra.Command{
 			if err != nil {
 				return err
 			}
-			if _, err := dinosql.ParseQueries(c, settings, pkg); err != nil {
+			if _, err := dinosql.ParseQueries(c, pkg); err != nil {
 				return err
 			}
 		}

internal/cmd/cmd.go

@@ -12,7 +12,6 @@ import (
 func TestFuncs(t *testing.T) {
 	_, err := ParseQueries(
 		pg.NewCatalog(),
-		GenerateSettings{},
 		PackageSettings{
 			Queries: filepath.Join("testdata", "funcs"),
 		},

internal/dinosql/checks_test.go

@@ -5,20 +5,45 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"path/filepath"
 	"strings"
 
 	"github.com/kyleconroy/sqlc/internal/pg"
 )
 
+const errMessageNoVersion = `The configuration file must have a version number.
+Set the version to 1 at the top of sqlc.json:
+
+{
+  "version": "1"
+  ...
+}
+`
+
+const errMessageUnknownVersion = `The configuration file has an invalid version number.
+The only supported version is "1".
+`
+
+const errMessageNoPackages = `No packages are configured`
+
 type GenerateSettings struct {
-	Version   string            `json:"version"`
-	Packages  []PackageSettings `json:"packages"`
-	Overrides []Override        `json:"overrides,omitempty"`
-	Rename    map[string]string `json:"rename,omitempty"`
+	Version    string            `json:"version"`
+	Packages   []PackageSettings `json:"packages"`
+	Overrides  []Override        `json:"overrides,omitempty"`
+	Rename     map[string]string `json:"rename,omitempty"`
+	PackageMap map[string]PackageSettings
 }
 
+type Engine string
+
+const (
+	EngineMySQL      Engine = "mysql"
+	EnginePostgreSQL Engine = "postgresql"
+)
+
 type PackageSettings struct {
 	Name                string     `json:"name"`
+	Engine              Engine     `json:"engine,omitempty"`
 	Path                string     `json:"path"`
 	Schema              string     `json:"schema"`
 	Queries             string     `json:"queries"`
@@ -96,6 +121,8 @@ func (o *Override) Parse() error {
 var ErrMissingVersion = errors.New("no version number")
 var ErrUnknownVersion = errors.New("invalid version number")
 var ErrNoPackages = errors.New("no packages")
+var ErrNoPackageName = errors.New("missing package name")
+var ErrNoPackagePath = errors.New("missing package path")
 
 func ParseConfig(rd io.Reader) (GenerateSettings, error) {
 	dec := json.NewDecoder(rd)
@@ -119,11 +146,36 @@ func ParseConfig(rd io.Reader) (GenerateSettings, error) {
 		}
 	}
 	for j := range config.Packages {
+		if config.Packages[j].Path == "" {
+			return config, ErrNoPackagePath
+		}
 		for i := range config.Packages[j].Overrides {
 			if err := config.Packages[j].Overrides[i].Parse(); err != nil {
 				return config, err
 			}
 		}
+		if config.Packages[j].Name == "" {
+			config.Packages[j].Name = filepath.Base(config.Packages[j].Path)
+		}
+		if config.Packages[j].Engine == "" {
+			config.Packages[j].Engine = EnginePostgreSQL
+		}
 	}
-	return config, nil
+	err := config.PopulatePkgMap()
+
+	return config, err
+}
+
+func (s *GenerateSettings) PopulatePkgMap() error {
+	packageMap := make(map[string]PackageSettings)
+
+	for _, c := range s.Packages {
+		if c.Name == "" {
+			return ErrNoPackageName
+		}
+		packageMap[c.Name] = c
+	}
+	s.PackageMap = packageMap
+
+	return nil
 }