Add WAIT_AT_LOW_PRIORITY parsing for ALTER TABLE SWITCH

Support MAX_DURATION and ABORT_AFTER_WAIT options within WAIT_AT_LOW_PRIORITY
clause for table switch operations.

Author: claude

ast/alter_table_switch_statement.go

@@ -28,7 +28,16 @@ type TruncateTargetTableSwitchOption struct {
 func (o *TruncateTargetTableSwitchOption) tableSwitchOption() {}
 func (o *TruncateTargetTableSwitchOption) node()              {}
 
-// LowPriorityLockWait represents LOW_PRIORITY_LOCK_WAIT option
+// LowPriorityLockWaitTableSwitchOption represents WAIT_AT_LOW_PRIORITY option
+type LowPriorityLockWaitTableSwitchOption struct {
+	OptionKind string
+	Options    []LowPriorityLockWaitOption
+}
+
+func (o *LowPriorityLockWaitTableSwitchOption) tableSwitchOption() {}
+func (o *LowPriorityLockWaitTableSwitchOption) node()              {}
+
+// LowPriorityLockWait represents LOW_PRIORITY_LOCK_WAIT option (legacy)
 type LowPriorityLockWait struct {
 	MaxDuration       ScalarExpression
 	MaxDurationUnit   string // "MINUTES", "SECONDS"

ast/drop_statements.go

@@ -123,7 +123,7 @@ type LowPriorityLockWaitOption interface {
 
 // LowPriorityLockWaitMaxDurationOption represents MAX_DURATION option
 type LowPriorityLockWaitMaxDurationOption struct {
-	MaxDuration *IntegerLiteral
+	MaxDuration ScalarExpression
 	Unit        string // Minutes or Seconds
 	OptionKind  string // MaxDuration
 }

parser/marshal.go

@@ -11653,6 +11653,19 @@ func tableSwitchOptionToJSON(opt ast.TableSwitchOption) jsonNode {
 			"TruncateTarget": o.TruncateTarget,
 			"OptionKind":     o.OptionKind,
 		}
+	case *ast.LowPriorityLockWaitTableSwitchOption:
+		node := jsonNode{
+			"$type":      "LowPriorityLockWaitTableSwitchOption",
+			"OptionKind": o.OptionKind,
+		}
+		if len(o.Options) > 0 {
+			opts := make([]jsonNode, len(o.Options))
+			for i, subOpt := range o.Options {
+				opts[i] = lowPriorityLockWaitOptionToJSON(subOpt)
+			}
+			node["Options"] = opts
+		}
+		return node
 	default:
 		return jsonNode{"$type": "UnknownSwitchOption"}
 	}

parser/parse_ddl.go

@@ -3594,6 +3594,72 @@ func (p *Parser) parseAlterTableSwitchStatement(tableName *ast.SchemaObjectName)
 						}
 						stmt.Options = append(stmt.Options, opt)
 					}
+				} else if optionName == "WAIT_AT_LOW_PRIORITY" {
+					opt := &ast.LowPriorityLockWaitTableSwitchOption{
+						OptionKind: "LowPriorityLockWait",
+					}
+
+					// Expect (
+					if p.curTok.Type == TokenLParen {
+						p.nextToken()
+
+						for p.curTok.Type != TokenRParen && p.curTok.Type != TokenEOF {
+							subOptName := strings.ToUpper(p.curTok.Literal)
+							p.nextToken()
+
+							if subOptName == "MAX_DURATION" {
+								if p.curTok.Type == TokenEquals {
+									p.nextToken()
+								}
+								// Parse the duration value
+								durExpr, err := p.parseScalarExpression()
+								if err != nil {
+									return nil, err
+								}
+								subOpt := &ast.LowPriorityLockWaitMaxDurationOption{
+									OptionKind:  "MaxDuration",
+									MaxDuration: durExpr,
+								}
+								// Check for MINUTES
+								if strings.ToUpper(p.curTok.Literal) == "MINUTES" {
+									subOpt.Unit = "Minutes"
+									p.nextToken()
+								}
+								opt.Options = append(opt.Options, subOpt)
+							} else if subOptName == "ABORT_AFTER_WAIT" {
+								if p.curTok.Type == TokenEquals {
+									p.nextToken()
+								}
+								value := p.curTok.Literal
+								p.nextToken()
+								// Convert to proper case
+								abortValue := "None"
+								switch strings.ToUpper(value) {
+								case "NONE":
+									abortValue = "None"
+								case "SELF":
+									abortValue = "Self"
+								case "BLOCKERS":
+									abortValue = "Blockers"
+								}
+								subOpt := &ast.LowPriorityLockWaitAbortAfterWaitOption{
+									OptionKind:     "AbortAfterWait",
+									AbortAfterWait: abortValue,
+								}
+								opt.Options = append(opt.Options, subOpt)
+							}
+
+							if p.curTok.Type == TokenComma {
+								p.nextToken()
+							}
+						}
+
+						if p.curTok.Type == TokenRParen {
+							p.nextToken()
+						}
+					}
+
+					stmt.Options = append(stmt.Options, opt)
 				}
 
 				if p.curTok.Type == TokenComma {

parser/testdata/AlterTableSwitchStatementTests120/metadata.json

@@ -1 +1 @@
-{"todo": true}
+{}

parser/testdata/Baselines120_AlterTableSwitchStatementTests120/metadata.json

@@ -1 +1 @@
-{"todo": true}
+{}