Database Operations

/**
 * MySQL-specific database implementation
 * Handles MySQL-specific behavior, version detection, and cluster environments
 */
public class MySQLDatabase extends Database<MySQLConnection> {
    
    /**
     * Creates a new MySQL database instance
     * @param configuration Flyway configuration
     * @param jdbcConnectionFactory JDBC connection factory
     * @param statementInterceptor Statement interceptor for monitoring
     */
    public MySQLDatabase(Configuration configuration, JdbcConnectionFactory jdbcConnectionFactory, StatementInterceptor statementInterceptor);
    
    /**
     * Returns WSREP status for cluster environments
     * @return true if WSREP_ON=ON (for MariaDB clusters)
     */
    public boolean isWsrepOn();
    
    /**
     * Extracts MySQL version from SELECT VERSION() output
     * @param selectVersionOutput Raw version string from database
     * @return Parsed MigrationVersion
     * @throws FlywayException if version cannot be determined
     */
    public static MigrationVersion extractMySQLVersionFromString(String selectVersionOutput);
    
    /**
     * Extracts MariaDB version from SELECT VERSION() output
     * Handles both standard MariaDB and MaxScale proxy scenarios
     * @param selectVersionOutput Raw version string from database
     * @return Parsed MigrationVersion
     * @throws FlywayException if version cannot be determined
     */
    public static MigrationVersion extractMariaDBVersionFromString(String selectVersionOutput);
    
    /**
     * Detects if running in Percona XtraDB Cluster with strict mode
     * @param jdbcTemplate JDBC template for queries
     * @return true if PXC strict mode is ENFORCING or MASTER
     */
    public static boolean isRunningInPerconaXtraDBClusterWithStrictMode(JdbcTemplate jdbcTemplate);
    
    /**
     * Detects if WSREP is enabled (for MariaDB Galera clusters)
     * @param jdbcTemplate JDBC template for queries
     * @return true if @@GLOBAL.WSREP_ON is ON
     */
    static boolean isWsrepOn(JdbcTemplate jdbcTemplate);
    
    /**
     * Detects if GTID consistency is enforced
     * @param jdbcTemplate JDBC template for queries
     * @return true if @@GLOBAL.ENFORCE_GTID_CONSISTENCY is ON
     */
    public static boolean isRunningInGTIDConsistencyMode(JdbcTemplate jdbcTemplate);
    
    /**
     * Returns the constraint name for MySQL primary keys
     * @param tableName Name of the table
     * @return Quoted constraint name in format `tableName_pk`
     */
    protected String getConstraintName(String tableName);
    
    /**
     * Creates MySQL-specific connection instance
     * @param connection Raw JDBC connection
     * @return MySQLConnection instance
     */
    @Override
    protected MySQLConnection doGetConnection(Connection connection);
    
    /**
     * Determines database version from SELECT VERSION() output
     * Handles both MySQL and MariaDB version detection
     * @return Parsed MigrationVersion
     */
    @Override
    protected MigrationVersion determineVersion();
    
    /**
     * Ensures MySQL/MariaDB version is supported by Flyway
     * @param configuration Flyway configuration for edition checks
     */
    @Override
    public void ensureSupported(Configuration configuration);
    
    /**
     * Returns current database user
     * @return Username portion from USER() function
     * @throws SQLException if query fails
     */
    @Override
    protected String doGetCurrentUser() throws SQLException;
    
    /**
     * MySQL does not support DDL transactions
     * @return false (MySQL auto-commits DDL)
     */
    @Override
    public boolean supportsDdlTransactions();
    
    /**
     * Returns MySQL boolean true representation
     * @return "1"
     */
    @Override
    public String getBooleanTrue();
    
    /**
     * Returns MySQL boolean false representation
     * @return "0"
     */
    @Override
    public String getBooleanFalse();
    
    /**
     * Returns MySQL identifier quote character
     * @return "`" (backtick)
     */
    @Override
    public String getOpenQuote();
    
    /**
     * Returns MySQL identifier quote character
     * @return "`" (backtick)
     */
    @Override
    public String getCloseQuote();
    
    /**
     * MySQL treats database as schema
     * @return true
     */
    @Override
    public boolean catalogIsSchema();
    
    /**
     * Determines if single connection should be used
     * @return false for PXC strict mode, true otherwise
     */
    @Override
    public boolean useSingleConnection();
    
    /**
     * Detects cloud hosting environment
     * @return "AWS RDS" if detected, otherwise default hosting
     */
    @Override
    public String getDatabaseHosting();
    
    /**
     * Determines if CREATE TABLE AS SELECT is allowed
     * @return false for PXC strict mode and GTID consistency, true otherwise
     */
    protected boolean isCreateTableAsSelectAllowed();
    
    // Package-private methods for internal use
    boolean isMySQL();
    boolean isMariaDB();
    boolean isPxcStrict();
}

// Automatic creation via DatabaseType
MySQLDatabaseType dbType = new MySQLDatabaseType();
MySQLDatabase database = (MySQLDatabase) dbType.createDatabase(configuration, jdbcFactory, interceptor);

// Environment detection
boolean isCluster = database.isWsrepOn();
boolean hasGtid = MySQLDatabase.isRunningInGTIDConsistencyMode(jdbcTemplate);

// Version parsing
String versionOutput = "8.0.28-0ubuntu0.20.04.3";
MigrationVersion version = MySQLDatabase.extractMySQLVersionFromString(versionOutput);

String mariaVersionOutput = "10.6.7-MariaDB-2ubuntu1.1";
MigrationVersion mariaVersion = MySQLDatabase.extractMariaDBVersionFromString(mariaVersionOutput);

/**
 * MariaDB-specific database implementation
 * Extends MySQLDatabase with MariaDB-specific behavior
 */
public class MariaDBDatabase extends MySQLDatabase {
    
    /**
     * Creates a new MariaDB database instance
     * @param configuration Flyway configuration
     * @param jdbcConnectionFactory JDBC connection factory
     * @param statementInterceptor Statement interceptor for monitoring
     */
    public MariaDBDatabase(Configuration configuration, JdbcConnectionFactory jdbcConnectionFactory, StatementInterceptor statementInterceptor);
    
    /**
     * Returns constraint name format for MariaDB
     * MariaDB returns empty string for constraint names
     * @param tableName Name of the table
     * @return Empty string (MariaDB-specific behavior)
     */
    @Override
    protected String getConstraintName(String tableName);
    
    /**
     * Ensures MariaDB version is supported
     * Checks minimum version requirements and edition compatibility
     * @param configuration Flyway configuration for edition checks
     */
    @Override
    public void ensureSupported(Configuration configuration);
}

// Automatic creation via MariaDBDatabaseType
MariaDBDatabaseType dbType = new MariaDBDatabaseType();
MariaDBDatabase database = (MariaDBDatabase) dbType.createDatabase(configuration, jdbcFactory, interceptor);

// MariaDB-specific behavior
String constraintName = database.getConstraintName("my_table"); // Returns ""

// Check for PXC strict mode
boolean isPxcStrict = MySQLDatabase.isRunningInPerconaXtraDBClusterWithStrictMode(jdbcTemplate);

// PXC strict mode affects:
// - CREATE TABLE AS SELECT operations (not allowed)
// - Single connection usage (required)

// Check for WSREP (MariaDB Galera)
boolean isWsrepOn = MySQLDatabase.isWsrepOn(jdbcTemplate);

// WSREP affects various operations and cluster behavior

// Check for GTID consistency
boolean hasGtidConsistency = MySQLDatabase.isRunningInGTIDConsistencyMode(jdbcTemplate);

// GTID consistency affects:
// - CREATE TABLE AS SELECT operations (not allowed)
// - Transaction handling

// Standard MySQL versions
String version1 = "8.0.28";
String version2 = "5.7.36-log";
String version3 = "8.0.28-0ubuntu0.20.04.3";

MigrationVersion v1 = MySQLDatabase.extractMySQLVersionFromString(version1); // 8.0
MigrationVersion v2 = MySQLDatabase.extractMySQLVersionFromString(version2); // 5.7
MigrationVersion v3 = MySQLDatabase.extractMySQLVersionFromString(version3); // 8.0

// Standard MariaDB
String mariaVersion1 = "10.6.7-MariaDB";
String mariaVersion2 = "10.5.15-1-MariaDB-enterprise";

// MaxScale proxy scenario
String maxScaleVersion = "10.6.7-2 2.5.11-maxscale";

MigrationVersion mv1 = MySQLDatabase.extractMariaDBVersionFromString(mariaVersion1); // 10.6
MigrationVersion mv2 = MySQLDatabase.extractMariaDBVersionFromString(mariaVersion2); // 10.5
MigrationVersion mv3 = MySQLDatabase.extractMariaDBVersionFromString(maxScaleVersion); // 10.6

// MySQL does not support DDL transactions
database.supportsDdlTransactions(); // Returns false

// MySQL uses backticks for identifiers
String openQuote = database.getOpenQuote();   // Returns "`"
String closeQuote = database.getCloseQuote(); // Returns "`"

// MySQL boolean representation
String trueValue = database.getBooleanTrue();   // Returns "1"
String falseValue = database.getBooleanFalse(); // Returns "0"

// MySQL treats catalog as schema
boolean catalogIsSchema = database.catalogIsSchema(); // Returns true

// Connection usage depends on environment
boolean useSingleConnection = database.useSingleConnection();
// Returns false for PXC strict mode, true otherwise

// Check if running on AWS RDS
String hosting = database.getDatabaseHosting();
// Returns "AWS RDS" if detected, otherwise default hosting

// Get raw CREATE TABLE script for history table
Table historyTable = schema.getTable("flyway_schema_history");
String createScript = database.getRawCreateScript(historyTable, false);

// For baseline scenarios
String baselineScript = database.getRawCreateScript(historyTable, true);