parseConnectByCondition parses the condition expression for CONNECT BY. It handles the PRIOR prefix operator in either position: CONNECT BY PRIOR id = parent_id (PRIOR on left) CONNECT BY id = PRIOR parent_id (PRIOR on right) CONNECT BY PRIOR id = parent_id AND active = 1 (c
()
| 362 | // PRIOR references the value from the parent row in the hierarchy. |
| 363 | // It is modeled as UnaryExpression{Operator: ast.Prior, Expr: <column>}. |
| 364 | func (p *Parser) parseConnectByCondition() (ast.Expression, error) { |
| 365 | var base ast.Expression |
| 366 | |
| 367 | // Case 1: PRIOR col op col |
| 368 | if strings.EqualFold(p.currentToken.Token.Value, "PRIOR") { |
| 369 | p.advance() |
| 370 | priorIdent := p.parseIdent() |
| 371 | if priorIdent == nil || priorIdent.Name == "" { |
| 372 | return nil, p.expectedError("column name after PRIOR") |
| 373 | } |
| 374 | priorExpr := &ast.UnaryExpression{Operator: ast.Prior, Expr: priorIdent} |
| 375 | |
| 376 | if p.isType(models.TokenTypeEq) || p.isType(models.TokenTypeNeq) || |
| 377 | p.isType(models.TokenTypeLt) || p.isType(models.TokenTypeGt) || |
| 378 | p.isType(models.TokenTypeLtEq) || p.isType(models.TokenTypeGtEq) { |
| 379 | op := p.currentToken.Token.Value |
| 380 | p.advance() |
| 381 | right, err := p.parsePrimaryExpression() |
| 382 | if err != nil { |
| 383 | return nil, err |
| 384 | } |
| 385 | base = &ast.BinaryExpression{Left: priorExpr, Operator: op, Right: right} |
| 386 | } else { |
| 387 | base = priorExpr |
| 388 | } |
| 389 | } else { |
| 390 | // Case 2: col op PRIOR col (PRIOR on the right-hand side) |
| 391 | // or plain expression (no PRIOR) |
| 392 | left, err := p.parsePrimaryExpression() |
| 393 | if err != nil { |
| 394 | return nil, err |
| 395 | } |
| 396 | if p.isType(models.TokenTypeEq) || p.isType(models.TokenTypeNeq) || |
| 397 | p.isType(models.TokenTypeLt) || p.isType(models.TokenTypeGt) || |
| 398 | p.isType(models.TokenTypeLtEq) || p.isType(models.TokenTypeGtEq) { |
| 399 | op := p.currentToken.Token.Value |
| 400 | p.advance() |
| 401 | // Check for PRIOR on the right side |
| 402 | if strings.EqualFold(p.currentToken.Token.Value, "PRIOR") { |
| 403 | p.advance() |
| 404 | priorIdent := p.parseIdent() |
| 405 | if priorIdent == nil || priorIdent.Name == "" { |
| 406 | return nil, p.expectedError("column name after PRIOR") |
| 407 | } |
| 408 | priorExpr := &ast.UnaryExpression{Operator: ast.Prior, Expr: priorIdent} |
| 409 | base = &ast.BinaryExpression{Left: left, Operator: op, Right: priorExpr} |
| 410 | } else { |
| 411 | right, err := p.parsePrimaryExpression() |
| 412 | if err != nil { |
| 413 | return nil, err |
| 414 | } |
| 415 | base = &ast.BinaryExpression{Left: left, Operator: op, Right: right} |
| 416 | } |
| 417 | } else { |
| 418 | base = left |
| 419 | } |
| 420 | } |
| 421 |
no test coverage detected