Add comprehensive test coverage for EXEC prepare method

[Ananya2]

Overview

The PrepareMethodExecTest.java test suite provides comprehensive validation for the EXEC prepare method implementation in the Microsoft SQL Server JDBC Driver. This implementation specifically addresses Sybase ASE compatibility requirements, enabling seamless migration from Sybase environments to SQL Server by maintaining session-scoped temporary table persistence across PreparedStatement boundaries.

Test Strategy

The testing strategy follows a multi-layered approach covering:

1. Core Functionality Validation - Primary Sybase ASE compatibility requirements
2. Comprehensive Data Type Testing - All supported SQL data types with edge cases
3. Security Validation - SQL injection prevention across attack vectors
4. Performance Assessment - Comparative analysis with existing prepare methods
5. Edge Case Handling - Boundary conditions and error scenarios
6. Real-world Migration Scenarios - Complex Sybase migration patterns

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Test Scenarios by Category

Category 1: Core Sybase ASE Compatibility

Scenario 1.1: Temporary Table Persistence

• Test Method: testTempTablePersistenceWithExecMethod()
• Business Logic: Validates that temporary tables created in one PreparedStatement remain accessible across different PreparedStatements within the same session
• Impact: Critical - This is the primary differentiator for Sybase migration. Traditional prepare and prepexec methods would fail this scenario
• Test Flow:
  1. Create temporary table using EXEC method
  2. Insert data using different PreparedStatement
  3. Query data using third PreparedStatement
  4. Update data using fourth PreparedStatement
  5. Verify persistence across all operations
• Validation: Ensures temp tables persist in session scope, enabling complex Sybase migration scenarios

Scenario 1.2: Complex Multi-Table Operations

• Test Method: testMultipleTempTablesScenario()
• Business Logic: Simulates real-world Sybase migration scenarios involving multiple temporary tables with JOIN operations
• Impact: High - Validates complex migration patterns common in Sybase applications
• Test Flow:
  1. Create multiple temporary tables (#orders, #customers)
  2. Insert data into both tables using separate PreparedStatements
  3. Execute complex JOIN queries across temporary tables
  4. Verify data integrity and accessibility
• Validation: Confirms that EXEC method supports complex temporary table workflows essential for Sybase migration

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Category 2: Security Validation

Scenario 2.1: Basic SQL Injection Prevention

• Test Method: testSQLInjectionPrevention()
• Business Logic: Validates that EXEC method properly escapes parameters to prevent SQL injection attacks
• Impact: Critical - Ensures security parity with existing prepare methods
• Attack Vectors Tested:
  • Classic injection: '; DROP TABLE users; --
  • Boolean-based: ' OR '1'='1
  • Comment-based: admin'/*
  • Command execution: 1'; EXEC xp_cmdshell('dir'); --
• Validation: All injection attempts return as literal strings, not executed code

Scenario 2.2: Advanced Attack Pattern Prevention

• Test Method: testAdvancedSQLInjectionPrevention()
• Business Logic: Tests sophisticated attack patterns that bypass basic filters
• Impact: High - Protects against advanced persistent threats
• Advanced Patterns Tested:
  • Time-based attacks: '; WAITFOR DELAY '00:00:05'; --
  • UNION-based attacks: ' UNION SELECT TOP 1 name FROM sys.tables --
  • System procedure attacks: '; EXEC sp_configure 'show advanced options', 1; --
  • Information extraction: ' AND (SELECT COUNT(*) FROM sys.tables) > 0 --
  • Variable declaration attacks: SQL variable manipulation attempts
• Validation: Ensures robust protection against enterprise-level security threats

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Category 3: Comprehensive Data Type Validation

Scenario 3.1: Multi-Data Type Parameter Substitution

• Test Method: testAllDataTypesParameterSubstitution()
• Business Logic: Validates parameter substitution for all supported SQL data types in a single comprehensive test
• Impact: High - Ensures complete data type compatibility for migration scenarios
• Data Types Covered: VARCHAR, NVARCHAR, INTEGER, DECIMAL, DATETIME, BINARY, BIT
• Test Sets:
  1. Normal Values: Standard data type values
  2. Edge Values: Boundary conditions (MAX_VALUE, special characters)
  3. NULL Values: NULL handling across all data types
  4. Extreme Values: Empty strings, mathematical scripts, zero values
  5. Injection Attempts: Security validation within data type context
• Validation: Confirms accurate parameter substitution and data integrity across all supported types

Scenario 3.2: Numeric Precision and Scale Handling

• Test Method: testNumericPrecisionScale()
• Business Logic: Validates that numeric precision and scale are preserved during parameter substitution
• Impact: Medium - Ensures financial and scientific data accuracy
• Precision Tests:
  • 123.456 (precision: 6, scale: 3)
  • 999999.999999 (precision: 12, scale: 6)
  • 0.000001 (precision: 7, scale: 6)
  • 123456789012345.123456789 (precision: 24, scale: 9)
• Validation: Confirms that decimal precision is maintained without data loss

Scenario 3.3: Unicode and International Character Support

• Test Method: testUnicodeEdgeCases()
• Business Logic: Validates proper handling of international characters, emojis, and special Unicode scenarios
• Impact: Medium - Essential for global applications and migration scenarios
• Unicode Categories Tested:
  • Emojis: 🌟🎯🔥
  • Latin with accents: Ñoño México
  • Cyrillic: Здравствуйте
  • Japanese: こんにちは
  • Mathematical scripts: 𝒪𝓃𝑒 𝒯𝓌𝑜
  • UTF-16 surrogates: Complex Unicode encoding
• Validation: Ensures proper character encoding and preservation across all Unicode categories

Scenario 3.4: Binary Data Edge Cases

• Test Method: testBinaryEdgeCases()
• Business Logic: Validates handling of binary data including full byte range and large binary objects
• Impact: Medium - Important for applications handling binary content (files, images, etc.)
• Binary Tests:
  • All byte values (0-255)
  • Large binary data (8KB)
  • Single byte values
  • Empty binary arrays
• Validation: Confirms accurate binary data preservation and retrieval

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Category 4: Date/Time and Large Value Handling

Scenario 4.1: DateTime Precision Validation

• Test Method: testDateTimePrecision()
• Business Logic: Validates microsecond precision and edge date handling
• Impact: Medium - Critical for time-sensitive applications and historical data
• DateTime Tests:
  • Microsecond precision: 2023-12-25 15:30:45.123456
  • Minimum SQL Server date: 1753-01-01 00:00:00.000
  • Maximum SQL Server date: 9999-12-31 23:59:59.997
• Validation: Ensures datetime precision is preserved within SQL Server limits

Scenario 4.2: Large Number Handling

• Test Method: testLargeNumbers()
• Business Logic: Validates handling of very large decimal numbers and scientific notation
• Impact: Low-Medium - Important for financial and scientific applications
• Large Number Tests:
  • Very large decimals with high precision
  • Very small decimals (micro-values)
  • Scientific notation: 1.23E+15
• Validation: Confirms numeric accuracy within SQL Server precision limits

Scenario 4.3: Long String Parameter Handling

• Test Method: testLongStringParameters()
• Business Logic: Validates handling of long string parameters across various lengths
• Impact: Medium - Important for applications with large text fields
• String Lengths Tested: 100, 1000, 4000, 8000 characters
• Validation: Ensures string truncation does not occur and full content is preserved

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Category 5: Performance and Scalability

Scenario 5.1: Comparative Performance Analysis

• Test Method: testBasicPerformanceComparison()
• Business Logic: Compares performance of EXEC method against PREPEXEC and PREPARE methods
• Impact: High - Validates that new method doesn't introduce significant performance degradation
• Performance Metrics:
  • 50 iterations of PreparedStatement creation and execution
  • Timing comparison across all three methods
  • Performance ratio validation (EXEC should be within 5x of other methods)
• Validation: Ensures EXEC method is performant enough for production use

Scenario 5.2: Repeated Execution Performance

• Test Method: testRepeatedExecutionPerformance()
• Business Logic: Tests performance when reusing the same PreparedStatement multiple times
• Impact: Medium - Validates efficiency in high-throughput scenarios
• Test Pattern:
  • Single PreparedStatement with 50 executions
  • Parameter reuse across executions
  • Memory and timing efficiency validation
• Validation: Confirms that EXEC method efficiently handles repeated executions

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Category 6: Advanced Operational Scenarios

Scenario 6.1: Batch Execution Support

• Test Method: testBatchExecution()
• Business Logic: Validates that EXEC method properly supports batch operations with temporary tables
• Impact: Medium - Important for bulk operations in migrated Sybase applications
• Batch Operations:
  • Create temporary table
  • Add multiple batch statements
  • Execute batch with executeBatch()
  • Verify all batch operations succeeded
• Validation: Ensures batch operations work correctly with temporary table persistence

Scenario 6.2: NULL Value Handling

• Test Method: testNullHandlingAllTypes()
• Business Logic: Validates proper NULL handling across all supported data types
• Impact: Medium - Ensures data integrity when dealing with optional/missing values
• NULL Tests:
  • NULL values for all major data types
  • wasNull() validation after retrieval
  • Mixed NULL and non-NULL scenarios
• Validation: Confirms proper NULL semantics are maintained