fork github.com/doug-martin

sql_dialect.go

@@ -0,0 +1,103 @@
+package db
+
+import (
+	"strings"
+	"sync"
+
+	"git.fsdpf.net/go/db/v2/exp"
+	"git.fsdpf.net/go/db/v2/internal/sb"
+	"git.fsdpf.net/go/db/v2/sqlgen"
+)
+
+type (
+	SQLDialectOptions = sqlgen.SQLDialectOptions
+	// An adapter interface to be used by a Dataset to generate SQL for a specific dialect.
+	// See DefaultAdapter for a concrete implementation and examples.
+	SQLDialect interface {
+		Dialect() string
+		ToSelectSQL(b sb.SQLBuilder, clauses exp.SelectClauses)
+		ToUpdateSQL(b sb.SQLBuilder, clauses exp.UpdateClauses)
+		ToInsertSQL(b sb.SQLBuilder, clauses exp.InsertClauses)
+		ToDeleteSQL(b sb.SQLBuilder, clauses exp.DeleteClauses)
+		ToTruncateSQL(b sb.SQLBuilder, clauses exp.TruncateClauses)
+	}
+	// The default adapter. This class should be used when building a new adapter. When creating a new adapter you can
+	// either override methods, or more typically update default values.
+	// See (github.com/doug-martin/goqu/dialect/postgres)
+	sqlDialect struct {
+		dialect        string
+		dialectOptions *SQLDialectOptions
+		selectGen      sqlgen.SelectSQLGenerator
+		updateGen      sqlgen.UpdateSQLGenerator
+		insertGen      sqlgen.InsertSQLGenerator
+		deleteGen      sqlgen.DeleteSQLGenerator
+		truncateGen    sqlgen.TruncateSQLGenerator
+	}
+)
+
+var (
+	dialects              = make(map[string]SQLDialect)
+	DefaultDialectOptions = sqlgen.DefaultDialectOptions
+	dialectsMu            sync.RWMutex
+)
+
+func init() {
+	RegisterDialect("default", DefaultDialectOptions())
+}
+
+func RegisterDialect(name string, do *SQLDialectOptions) {
+	dialectsMu.Lock()
+	defer dialectsMu.Unlock()
+	lowerName := strings.ToLower(name)
+	dialects[lowerName] = newDialect(lowerName, do)
+}
+
+func DeregisterDialect(name string) {
+	dialectsMu.Lock()
+	defer dialectsMu.Unlock()
+	delete(dialects, strings.ToLower(name))
+}
+
+func GetDialect(name string) SQLDialect {
+	name = strings.ToLower(name)
+	if d, ok := dialects[name]; ok {
+		return d
+	}
+	return newDialect("default", DefaultDialectOptions())
+}
+
+func newDialect(dialect string, do *SQLDialectOptions) SQLDialect {
+	return &sqlDialect{
+		dialect:        dialect,
+		dialectOptions: do,
+		selectGen:      sqlgen.NewSelectSQLGenerator(dialect, do),
+		updateGen:      sqlgen.NewUpdateSQLGenerator(dialect, do),
+		insertGen:      sqlgen.NewInsertSQLGenerator(dialect, do),
+		deleteGen:      sqlgen.NewDeleteSQLGenerator(dialect, do),
+		truncateGen:    sqlgen.NewTruncateSQLGenerator(dialect, do),
+	}
+}
+
+func (d *sqlDialect) Dialect() string {
+	return d.dialect
+}
+
+func (d *sqlDialect) ToSelectSQL(b sb.SQLBuilder, clauses exp.SelectClauses) {
+	d.selectGen.Generate(b, clauses)
+}
+
+func (d *sqlDialect) ToUpdateSQL(b sb.SQLBuilder, clauses exp.UpdateClauses) {
+	d.updateGen.Generate(b, clauses)
+}
+
+func (d *sqlDialect) ToInsertSQL(b sb.SQLBuilder, clauses exp.InsertClauses) {
+	d.insertGen.Generate(b, clauses)
+}
+
+func (d *sqlDialect) ToDeleteSQL(b sb.SQLBuilder, clauses exp.DeleteClauses) {
+	d.deleteGen.Generate(b, clauses)
+}
+
+func (d *sqlDialect) ToTruncateSQL(b sb.SQLBuilder, clauses exp.TruncateClauses) {
+	d.truncateGen.Generate(b, clauses)
+}