fork github.com/doug-martin

2025-03-22 23:02:05 +08:00
commit f14642a736
131 changed files with 34555 additions and 0 deletions
@@ -0,0 +1,155 @@
+package sqlgen
+
+import (
+	"git.fsdpf.net/go/db/v2/exp"
+	"git.fsdpf.net/go/db/v2/internal/errors"
+	"git.fsdpf.net/go/db/v2/internal/sb"
+)
+
+var ErrNoUpdatedValuesProvided = errors.New("no update values provided")
+
+func ErrCTENotSupported(dialect string) error {
+	return errors.New("dialect does not support CTE WITH clause [dialect=%s]", dialect)
+}
+
+func ErrRecursiveCTENotSupported(dialect string) error {
+	return errors.New("dialect does not support CTE WITH RECURSIVE clause [dialect=%s]", dialect)
+}
+
+func ErrReturnNotSupported(dialect string) error {
+	return errors.New("dialect does not support RETURNING clause [dialect=%s]", dialect)
+}
+
+func ErrNotSupportedFragment(sqlType string, f SQLFragmentType) error {
+	return errors.New("unsupported %s SQL fragment %s", sqlType, f)
+}
+
+type (
+	CommonSQLGenerator interface {
+		Dialect() string
+		DialectOptions() *SQLDialectOptions
+		ExpressionSQLGenerator() ExpressionSQLGenerator
+		ReturningSQL(b sb.SQLBuilder, returns exp.ColumnListExpression)
+		FromSQL(b sb.SQLBuilder, from exp.ColumnListExpression)
+		SourcesSQL(b sb.SQLBuilder, from exp.ColumnListExpression)
+		WhereSQL(b sb.SQLBuilder, where exp.ExpressionList)
+		OrderSQL(b sb.SQLBuilder, order exp.ColumnListExpression)
+		OrderWithOffsetFetchSQL(b sb.SQLBuilder, order exp.ColumnListExpression, offset uint, limit interface{})
+		LimitSQL(b sb.SQLBuilder, limit interface{})
+		UpdateExpressionSQL(b sb.SQLBuilder, updates ...exp.UpdateExpression)
+	}
+	commonSQLGenerator struct {
+		dialect        string
+		esg            ExpressionSQLGenerator
+		dialectOptions *SQLDialectOptions
+	}
+)
+
+func NewCommonSQLGenerator(dialect string, do *SQLDialectOptions) CommonSQLGenerator {
+	return &commonSQLGenerator{dialect: dialect, esg: NewExpressionSQLGenerator(dialect, do), dialectOptions: do}
+}
+
+func (csg *commonSQLGenerator) Dialect() string {
+	return csg.dialect
+}
+
+func (csg *commonSQLGenerator) DialectOptions() *SQLDialectOptions {
+	return csg.dialectOptions
+}
+
+func (csg *commonSQLGenerator) ExpressionSQLGenerator() ExpressionSQLGenerator {
+	return csg.esg
+}
+
+func (csg *commonSQLGenerator) ReturningSQL(b sb.SQLBuilder, returns exp.ColumnListExpression) {
+	if returns != nil && len(returns.Columns()) > 0 {
+		if csg.dialectOptions.SupportsReturn {
+			b.Write(csg.dialectOptions.ReturningFragment)
+			csg.esg.Generate(b, returns)
+		} else {
+			b.SetError(ErrReturnNotSupported(csg.dialect))
+		}
+	}
+}
+
+// Adds the FROM clause and tables to an sql statement
+func (csg *commonSQLGenerator) FromSQL(b sb.SQLBuilder, from exp.ColumnListExpression) {
+	if from != nil && !from.IsEmpty() {
+		b.Write(csg.dialectOptions.FromFragment)
+		csg.SourcesSQL(b, from)
+	}
+}
+
+// Adds the generates the SQL for a column list
+func (csg *commonSQLGenerator) SourcesSQL(b sb.SQLBuilder, from exp.ColumnListExpression) {
+	b.WriteRunes(csg.dialectOptions.SpaceRune)
+	csg.esg.Generate(b, from)
+}
+
+// Generates the WHERE clause for an SQL statement
+func (csg *commonSQLGenerator) WhereSQL(b sb.SQLBuilder, where exp.ExpressionList) {
+	if where != nil && !where.IsEmpty() {
+		b.Write(csg.dialectOptions.WhereFragment)
+		csg.esg.Generate(b, where)
+	}
+}
+
+// Generates the ORDER BY clause for an SQL statement
+func (csg *commonSQLGenerator) OrderSQL(b sb.SQLBuilder, order exp.ColumnListExpression) {
+	if order != nil && len(order.Columns()) > 0 {
+		b.Write(csg.dialectOptions.OrderByFragment)
+		csg.esg.Generate(b, order)
+	}
+}
+
+func (csg *commonSQLGenerator) OrderWithOffsetFetchSQL(
+	b sb.SQLBuilder,
+	order exp.ColumnListExpression,
+	offset uint,
+	limit interface{},
+) {
+	if order == nil {
+		return
+	}
+
+	csg.OrderSQL(b, order)
+	if offset > 0 {
+		b.Write(csg.dialectOptions.OffsetFragment)
+		csg.esg.Generate(b, offset)
+		b.Write([]byte(" ROWS"))
+
+		if limit != nil {
+			b.Write(csg.dialectOptions.FetchFragment)
+			csg.esg.Generate(b, limit)
+			b.Write([]byte(" ROWS ONLY"))
+		}
+	}
+}
+
+// Generates the LIMIT clause for an SQL statement
+func (csg *commonSQLGenerator) LimitSQL(b sb.SQLBuilder, limit interface{}) {
+	if limit != nil {
+		b.Write(csg.dialectOptions.LimitFragment)
+		if csg.dialectOptions.SurroundLimitWithParentheses {
+			b.WriteRunes(csg.dialectOptions.LeftParenRune)
+		}
+		csg.esg.Generate(b, limit)
+		if csg.dialectOptions.SurroundLimitWithParentheses {
+			b.WriteRunes(csg.dialectOptions.RightParenRune)
+		}
+	}
+}
+
+func (csg *commonSQLGenerator) UpdateExpressionSQL(b sb.SQLBuilder, updates ...exp.UpdateExpression) {
+	if len(updates) == 0 {
+		b.SetError(ErrNoUpdatedValuesProvided)
+		return
+	}
+	updateLen := len(updates)
+	for i, update := range updates {
+		csg.esg.Generate(b, update)
+		if i < updateLen-1 {
+			b.WriteRunes(csg.dialectOptions.CommaRune)
+		}
+	}
+}