#918 JDBC 4.5: Firebird-specific implementation of various enquote methods on Connection

Author: mrotteveel

src/docs/asciidoc/release_notes.adoc

@@ -44,6 +44,13 @@ The following has been changed or fixed since Jaybird 5.0.10:
 +
 Applications referencing this constant may need to be recompiled to function correctly with Jaybird 5.0.12 and higher.
 If you use Java 26 or higher, we recommend using `java.sql.Type.DECFLOAT` and `java.sql.JDBCType.DECFLOAT` instead.
+* JDBC 4.5 support: implemented methods `enquoteIdentifier`, `enquoteLiteral`, `enquoteNCharLiteral`, and `isSimpleIdentifier` on `FBConnection`, and added them to interface `FirebirdConnection` so for older Java versions (https://github.com/FirebirdSQL/jaybird/issues/908[#908])
++
+The methods of the same name in the `java.sql.Statement` implementations now call the methods on the connection.
+This results in two minor breaking changes:
++
+** Reserved words are no longer considered simple identifiers by `enquoteIdentifier` and `isSimpleIdentifier` and will be quoted (or -- for dialect 1 -- result in a `SQLFeatureNotSupportedException`)
+** Presence of the NUL character (U+0000) in an identifier passed to `enquoteIdentifier` will result in a `SQLSyntaxErrorException`
 
 [#jaybird-5-0-11-changelog]
 === Jaybird 5.0.11
@@ -436,11 +443,13 @@ Specifically affected are:
 At this time, Jaybird still uses its own constants in `JaybirdType.DECFLOAT` and `JaybirdTypeCodes.DECFLOAT` with value `-6001`.
 This value will be changed to match the JDBC specified value, and the constants deprecated, in a future maintenance release of Jaybird.
 +
-Addressed in Jaybird 6.0.5.
+Addressed in Jaybird 5.0.12.
 * Introduction of new methods on `java.sql.Connection` -- `enquoteIdentifier`, `enquoteLiteral`, `enquoteNCharLiteral`, and `isSimpleIdentifier`
 +
 The default implementation provided is not sufficient for Firebird, especially not when connecting to a dialect 1 database.
 For the time being, we recommend using the equivalent JDBC 4.3 methods (with the same name) on a `java.sql.Statement` instance of the connection.
++
+Addressed in Jaybird 5.0.12
 * The JDBC escape to selectively disable escape processing ([.nowrap]`++{\ ... \}++`) is not yet implemented.
 
 We plan to address these issues in Jaybird 5 and Jaybird 6 maintenance releases _after_ the release of Java 26 (tracked by https://github.com/FirebirdSQL/jaybird/issues/907[#907]).

src/main/org/firebirdsql/gds/JaybirdErrorCodes.java

@@ -102,6 +102,9 @@ public interface JaybirdErrorCodes {
     int jb_localTransactionActive   = 337248309;
     // gaps due to selective backporting
     int jb_invalidStringLength      = 337248330;
+    int jb_invalidIdentifierLength  = 337248350;
+    int jb_invalidIdentifierName    = 337248351;
+    int jb_noDelimitedIdentifiersInDialect1              = 337248352;
 
     @SuppressWarnings("unused")
     int jb_range_end                = 337264639;

src/main/org/firebirdsql/jaybird/parser/FirebirdReservedWords.java

@@ -30,15 +30,38 @@
 /**
  * All reserved words per Firebird version.
  *
- * @author <a href="mailto:mrotteveel@users.sourceforge.net">Mark Rotteveel</a>
+ * @author Mark Rotteveel
  * @since 5
  */
 @InternalApi
 public enum FirebirdReservedWords implements ReservedWords {
 
-    // TODO Add other versions if it turns out we do need reserved words per version
-    
-    FIREBIRD_5_0("ADD", "ADMIN", "ALL", "ALTER", "AND", "ANY", "AS", "AT", "AVG", "BEGIN", "BETWEEN", "BIGINT",
+    // Order is intentionally from higher versions to lower versions, see of(AbstractVersion) and latest()
+    FIREBIRD_5_0(5, 0, "ADD", "ADMIN", "ALL", "ALTER", "AND", "ANY", "AS", "AT", "AVG", "BEGIN", "BETWEEN", "BIGINT",
+            "BINARY", "BIT_LENGTH", "BLOB", "BOOLEAN", "BOTH", "BY", "CASE", "CAST", "CHAR", "CHARACTER",
+            "CHARACTER_LENGTH", "CHAR_LENGTH", "CHECK", "CLOSE", "COLLATE", "COLUMN", "COMMENT", "COMMIT", "CONNECT",
+            "CONSTRAINT", "CORR", "COUNT", "COVAR_POP", "COVAR_SAMP", "CREATE", "CROSS", "CURRENT",
+            "CURRENT_CONNECTION", "CURRENT_DATE", "CURRENT_ROLE", "CURRENT_TIME", "CURRENT_TIMESTAMP",
+            "CURRENT_TRANSACTION", "CURRENT_USER", "CURSOR", "DATE", "DAY", "DEC", "DECFLOAT", "DECIMAL", "DECLARE",
+            "DEFAULT", "DELETE", "DELETING", "DETERMINISTIC", "DISCONNECT", "DISTINCT", "DOUBLE", "DROP", "ELSE", "END",
+            "ESCAPE", "EXECUTE", "EXISTS", "EXTERNAL", "EXTRACT", "FALSE", "FETCH", "FILTER", "FLOAT", "FOR", "FOREIGN",
+            "FROM", "FULL", "FUNCTION", "GDSCODE", "GLOBAL", "GRANT", "GROUP", "HAVING", "HOUR", "IN", "INDEX", "INNER",
+            "INSENSITIVE", "INSERT", "INSERTING", "INT", "INT128", "INTEGER", "INTO", "IS", "JOIN", "LATERAL",
+            "LEADING", "LEFT", "LIKE", "LOCAL", "LOCALTIME", "LOCALTIMESTAMP", "LONG", "LOWER", "MAX", "MERGE", "MIN",
+            "MINUTE", "MONTH", "NATIONAL", "NATURAL", "NCHAR", "NO", "NOT", "NULL", "NUMERIC", "OCTET_LENGTH", "OF",
+            "OFFSET", "ON", "ONLY", "OPEN", "OR", "ORDER", "OUTER", "OVER", "PARAMETER", "PLAN", "POSITION",
+            "POST_EVENT", "PRECISION", "PRIMARY", "PROCEDURE", "PUBLICATION", "RDB$DB_KEY", "RDB$ERROR",
+            "RDB$GET_CONTEXT", "RDB$GET_TRANSACTION_CN", "RDB$RECORD_VERSION", "RDB$ROLE_IN_USE", "RDB$SET_CONTEXT",
+            "RDB$SYSTEM_PRIVILEGE", "REAL", "RECORD_VERSION", "RECREATE", "RECURSIVE", "REFERENCES", "REGR_AVGX",
+            "REGR_AVGY", "REGR_COUNT", "REGR_INTERCEPT", "REGR_R2", "REGR_SLOPE", "REGR_SXX", "REGR_SXY", "REGR_SYY",
+            "RELEASE", "RESETTING", "RETURN", "RETURNING_VALUES", "RETURNS", "REVOKE", "RIGHT", "ROLLBACK", "ROW",
+            "ROWS", "ROW_COUNT", "SAVEPOINT", "SCHEMA", "SCROLL", "SECOND", "SELECT", "SENSITIVE", "SET", "SIMILAR",
+            "SMALLINT", "SOME", "SQLCODE", "SQLSTATE", "START", "STDDEV_POP", "STDDEV_SAMP", "SUM", "TABLE", "THEN",
+            "TIME", "TIMESTAMP", "TIMEZONE_HOUR", "TIMEZONE_MINUTE", "TO", "TRAILING", "TRIGGER", "TRIM", "TRUE",
+            "UNBOUNDED", "UNION", "UNIQUE", "UNKNOWN", "UPDATE", "UPDATING", "UPPER", "USER", "USING", "VALUE",
+            "VALUES", "VARBINARY", "VARCHAR", "VARIABLE", "VARYING", "VAR_POP", "VAR_SAMP", "VIEW", "WHEN", "WHERE",
+            "WHILE", "WINDOW", "WITH", "WITHOUT", "YEAR"),
+    FIREBIRD_4_0(4, 0, "ADD", "ADMIN", "ALL", "ALTER", "AND", "ANY", "AS", "AT", "AVG", "BEGIN", "BETWEEN", "BIGINT",
             "BINARY", "BIT_LENGTH", "BLOB", "BOOLEAN", "BOTH", "BY", "CASE", "CAST", "CHAR", "CHARACTER",
             "CHARACTER_LENGTH", "CHAR_LENGTH", "CHECK", "CLOSE", "COLLATE", "COLUMN", "COMMENT", "COMMIT", "CONNECT",
             "CONSTRAINT", "CORR", "COUNT", "COVAR_POP", "COVAR_SAMP", "CREATE", "CROSS", "CURRENT",
@@ -62,14 +85,93 @@ public enum FirebirdReservedWords implements ReservedWords {
             "UNION", "UNIQUE", "UNKNOWN", "UPDATE", "UPDATING", "UPPER", "USER", "USING", "VALUE", "VALUES",
             "VARBINARY", "VARCHAR", "VARIABLE", "VARYING", "VAR_POP", "VAR_SAMP", "VIEW", "WHEN", "WHERE", "WHILE",
             "WINDOW", "WITH", "WITHOUT", "YEAR"),
+    FIREBIRD_3_0(3, 0, "ADD", "ADMIN", "ALL", "ALTER", "AND", "ANY", "AS", "AT", "AVG", "BEGIN", "BETWEEN", "BIGINT",
+            "BIT_LENGTH", "BLOB", "BOOLEAN", "BOTH", "BY", "CASE", "CAST", "CHAR", "CHARACTER", "CHARACTER_LENGTH",
+            "CHAR_LENGTH", "CHECK", "CLOSE", "COLLATE", "COLUMN", "COMMIT", "CONNECT", "CONSTRAINT", "CORR", "COUNT",
+            "COVAR_POP", "COVAR_SAMP", "CREATE", "CROSS", "CURRENT", "CURRENT_CONNECTION", "CURRENT_DATE",
+            "CURRENT_ROLE", "CURRENT_TIME", "CURRENT_TIMESTAMP", "CURRENT_TRANSACTION", "CURRENT_USER", "CURSOR",
+            "DATE", "DAY", "DEC", "DECIMAL", "DECLARE", "DEFAULT", "DELETE", "DELETING", "DETERMINISTIC", "DISCONNECT",
+            "DISTINCT", "DOUBLE", "DROP", "ELSE", "END", "ESCAPE", "EXECUTE", "EXISTS", "EXTERNAL", "EXTRACT", "FALSE",
+            "FETCH", "FILTER", "FLOAT", "FOR", "FOREIGN", "FROM", "FULL", "FUNCTION", "GDSCODE", "GLOBAL", "GRANT",
+            "GROUP", "HAVING", "HOUR", "IN", "INDEX", "INNER", "INSENSITIVE", "INSERT", "INSERTING", "INT", "INTEGER",
+            "INTO", "IS", "JOIN", "LEADING", "LEFT", "LIKE", "LONG", "LOWER", "MAX", "MERGE", "MIN", "MINUTE", "MONTH",
+            "NATIONAL", "NATURAL", "NCHAR", "NO", "NOT", "NULL", "NUMERIC", "OCTET_LENGTH", "OF", "OFFSET", "ON",
+            "ONLY", "OPEN", "OR", "ORDER", "OUTER", "OVER", "PARAMETER", "PLAN", "POSITION", "POST_EVENT", "PRECISION",
+            "PRIMARY", "PROCEDURE", "RDB$DB_KEY", "RDB$RECORD_VERSION", "REAL", "RECORD_VERSION", "RECREATE",
+            "RECURSIVE", "REFERENCES", "REGR_AVGX", "REGR_AVGY", "REGR_COUNT", "REGR_INTERCEPT", "REGR_R2",
+            "REGR_SLOPE", "REGR_SXX", "REGR_SXY", "REGR_SYY", "RELEASE", "RETURN", "RETURNING_VALUES", "RETURNS",
+            "REVOKE", "RIGHT", "ROLLBACK", "ROW", "ROWS", "ROW_COUNT", "SAVEPOINT", "SCROLL", "SECOND", "SELECT",
+            "SENSITIVE", "SET", "SIMILAR", "SMALLINT", "SOME", "SQLCODE", "SQLSTATE", "START", "STDDEV_POP",
+            "STDDEV_SAMP", "SUM", "TABLE", "THEN", "TIME", "TIMESTAMP", "TO", "TRAILING", "TRIGGER", "TRIM", "TRUE",
+            "UNION", "UNIQUE", "UNKNOWN", "UPDATE", "UPDATING", "UPPER", "USER", "USING", "VALUE", "VALUES", "VARCHAR",
+            "VARIABLE", "VARYING", "VAR_POP", "VAR_SAMP", "VIEW", "WHEN", "WHERE", "WHILE", "WITH", "YEAR"),
+    FIREBIRD_2_5(2, 5, "ADD", "ADMIN", "ALL", "ALTER", "AND", "ANY", "AS", "AT", "AVG", "BEGIN", "BETWEEN", "BIGINT",
+            "BIT_LENGTH", "BLOB", "BOTH", "BY", "CASE", "CAST", "CHAR", "CHARACTER", "CHARACTER_LENGTH", "CHAR_LENGTH",
+            "CHECK", "CLOSE", "COLLATE", "COLUMN", "COMMIT", "CONNECT", "CONSTRAINT", "COUNT", "CREATE", "CROSS",
+            "CURRENT", "CURRENT_CONNECTION", "CURRENT_DATE", "CURRENT_ROLE", "CURRENT_TIME", "CURRENT_TIMESTAMP",
+            "CURRENT_TRANSACTION", "CURRENT_USER", "CURSOR", "DATE", "DAY", "DEC", "DECIMAL", "DECLARE", "DEFAULT",
+            "DELETE", "DISCONNECT", "DISTINCT", "DOUBLE", "DROP", "ELSE", "END", "ESCAPE", "EXECUTE", "EXISTS",
+            "EXTERNAL", "EXTRACT", "FETCH", "FILTER", "FLOAT", "FOR", "FOREIGN", "FROM", "FULL", "FUNCTION", "GDSCODE",
+            "GLOBAL", "GRANT", "GROUP", "HAVING", "HOUR", "IN", "INDEX", "INNER", "INSENSITIVE", "INSERT", "INT",
+            "INTEGER", "INTO", "IS", "JOIN", "LEADING", "LEFT", "LIKE", "LOCALTIME", "LOCALTIMESTAMP", "LONG", "LOWER",
+            "MAX", "MAXIMUM_SEGMENT", "MERGE", "MIN", "MINUTE", "MONTH", "NATIONAL", "NATURAL", "NCHAR", "NO", "NOT",
+            "NULL", "NUMERIC", "OCTET_LENGTH", "OF", "ON", "ONLY", "OPEN", "OR", "ORDER", "OUTER", "PARAMETER", "PLAN",
+            "POSITION", "POST_EVENT", "PRECISION", "PRIMARY", "PROCEDURE", "RDB$DB_KEY", "REAL", "RECORD_VERSION",
+            "RECREATE", "RECURSIVE", "REFERENCES", "RELEASE", "RETURNING_VALUES", "RETURNS", "REVOKE", "RIGHT",
+            "ROLLBACK", "ROWS", "ROW_COUNT", "SAVEPOINT", "SECOND", "SELECT", "SENSITIVE", "SET", "SIMILAR", "SMALLINT",
+            "SOME", "SQLCODE", "SQLSTATE", "START", "SUM", "TABLE", "THEN", "TIME", "TIMESTAMP", "TO", "TRAILING",
+            "TRIGGER", "TRIM", "UNION", "UNIQUE", "UPDATE", "UPPER", "USER", "USING", "VALUE", "VALUES", "VARCHAR",
+            "VARIABLE", "VARYING", "VIEW", "WHEN", "WHERE", "WHILE", "WITH", "YEAR"),
+    FIREBIRD_2_1(2, 1, "ACTIVE", "ADD", "ADMIN", "AFTER", "ALL", "ALTER", "AND", "ANY", "AS", "ASC", "ASCENDING", "AT",
+            "AUTO", "AVG", "BEFORE", "BEGIN", "BETWEEN", "BIGINT", "BIT_LENGTH", "BLOB", "BOTH", "BY", "CASE", "CAST",
+            "CHAR", "CHARACTER", "CHARACTER_LENGTH", "CHAR_LENGTH", "CHECK", "CLOSE", "COLLATE", "COLUMN", "COMMIT",
+            "COMMITTED", "COMPUTED", "CONDITIONAL", "CONNECT", "CONSTRAINT", "CONTAINING", "COUNT", "CREATE", "CROSS",
+            "CSTRING", "CURRENT", "CURRENT_CONNECTION", "CURRENT_DATE", "CURRENT_ROLE", "CURRENT_TIME",
+            "CURRENT_TIMESTAMP", "CURRENT_TRANSACTION", "CURRENT_USER", "CURSOR", "DATABASE", "DATE", "DAY", "DEBUG",
+            "DEC", "DECIMAL", "DECLARE", "DEFAULT", "DELETE", "DESC", "DESCENDING", "DISCONNECT", "DISTINCT", "DO",
+            "DOMAIN", "DOUBLE", "DROP", "ELSE", "END", "ENTRY_POINT", "ESCAPE", "EXCEPTION", "EXECUTE", "EXISTS",
+            "EXIT", "EXTERNAL", "EXTRACT", "FETCH", "FILE", "FILTER", "FLOAT", "FOR", "FOREIGN", "FROM", "FULL",
+            "FUNCTION", "GDSCODE", "GENERATOR", "GEN_ID", "GLOBAL", "GRANT", "GROUP", "HAVING", "HOUR", "IF", "IN",
+            "INACTIVE", "INDEX", "INNER", "INPUT_TYPE", "INSENSITIVE", "INSERT", "INT", "INTEGER", "INTO", "IS",
+            "ISOLATION", "JOIN", "KEY", "LEADING", "LEFT", "LENGTH", "LEVEL", "LIKE", "LONG", "LOWER", "MANUAL", "MAX",
+            "MAXIMUM_SEGMENT", "MERGE", "MIN", "MINUTE", "MODULE_NAME", "MONTH", "NAMES", "NATIONAL", "NATURAL",
+            "NCHAR", "NO", "NOT", "NULL", "NUMERIC", "OCTET_LENGTH", "OF", "ON", "ONLY", "OPEN", "OPTION", "OR",
+            "ORDER", "OUTER", "OUTPUT_TYPE", "OVERFLOW", "PAGE", "PAGES", "PAGE_SIZE", "PARAMETER", "PASSWORD", "PLAN",
+            "POSITION", "POST_EVENT", "PRECISION", "PRIMARY", "PRIVILEGES", "PROCEDURE", "PROTECTED", "RDB$DB_KEY",
+            "READ", "REAL", "RECORD_VERSION", "RECREATE", "RECURSIVE", "REFERENCES", "RELEASE", "RESERV", "RESERVING",
+            "RETAIN", "RETURNING_VALUES", "RETURNS", "REVOKE", "RIGHT", "ROLLBACK", "ROWS", "ROW_COUNT", "SAVEPOINT",
+            "SCHEMA", "SECOND", "SEGMENT", "SELECT", "SENSITIVE", "SET", "SHADOW", "SHARED", "SINGULAR", "SIZE",
+            "SMALLINT", "SNAPSHOT", "SOME", "SORT", "SQLCODE", "STABILITY", "START", "STARTING", "STARTS", "STATISTICS",
+            "SUB_TYPE", "SUM", "SUSPEND", "TABLE", "THEN", "TIME", "TIMESTAMP", "TO", "TRAILING", "TRANSACTION",
+            "TRIGGER", "TRIM", "UNCOMMITTED", "UNION", "UNIQUE", "UPDATE", "UPPER", "USER", "USING", "VALUE", "VALUES",
+            "VARCHAR", "VARIABLE", "VARYING", "VIEW", "WAIT", "WHEN", "WHERE", "WHILE", "WITH", "WORK", "WRITE",
+            "YEAR"),
     ;
 
+    private final int major;
+    private final int minor;
     private final Set<CharSequence> reservedWords;
 
-    FirebirdReservedWords(CharSequence... reservedWords) {
+    FirebirdReservedWords(int major, int minor, CharSequence... reservedWords) {
+        this.major = major;
+        this.minor = minor;
         this.reservedWords = toUnmodifiableCaseInsensitiveSet(Arrays.asList(reservedWords));
     }
 
+    /**
+     * @return Firebird major version
+     */
+    int major() {
+        return major;
+    }
+
+    /**
+     * @return Firebird minor version
+     */
+    int minor() {
+        return minor;
+    }
+
     /**
      * Reserved words for latest known Firebird version.
      *
@@ -79,14 +181,36 @@ public static FirebirdReservedWords latest() {
         return FIREBIRD_5_0;
     }
 
+    /**
+     * Reserved words for the specified Firebird version.
+     *
+     * @param major
+     *         Firebird major version
+     * @param minor Firebird minor version
+     * @return reserved words for the specified version, or the closest known version
+     * @since 5.0.12
+     */
+    public static FirebirdReservedWords of(int major, int minor) {
+        FirebirdReservedWords[] values = values();
+        for (FirebirdReservedWords reservedWords : values) {
+            if (major > reservedWords.major ||
+                    major == reservedWords.major && minor >= reservedWords.minor) {
+                return reservedWords;
+            }
+        }
+        // fall back to the lowest known version
+        return values[values.length - 1];
+    }
+
     private static Set<CharSequence> toUnmodifiableCaseInsensitiveSet(Collection<CharSequence> values) {
         Set<CharSequence> set = new TreeSet<>(CharSequenceComparison.caseInsensitiveComparator());
         set.addAll(values);
         return unmodifiableSet(set);
     }
 
     @Override
-    public boolean isReservedWord(CharSequence tokenText) {
+    public final boolean isReservedWord(CharSequence tokenText) {
         return reservedWords.contains(tokenText);
     }
+
 }

src/main/org/firebirdsql/jdbc/FBConnection.java

@@ -44,7 +44,12 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
+import java.util.regex.Pattern;
 
+import static java.util.Objects.requireNonNull;
+import static org.firebirdsql.gds.JaybirdErrorCodes.jb_invalidIdentifierLength;
+import static org.firebirdsql.gds.JaybirdErrorCodes.jb_invalidIdentifierName;
+import static org.firebirdsql.gds.JaybirdErrorCodes.jb_noDelimitedIdentifiersInDialect1;
 import static org.firebirdsql.jdbc.SQLStateConstants.SQL_STATE_CONNECTION_CLOSED;
 
 /**
@@ -1277,6 +1282,65 @@ public int getNetworkTimeout() throws SQLException {
         return getFbDatabase().getNetworkTimeout();
     }
 
+    @Override
+    public final String enquoteLiteral(String val) throws SQLException {
+        if (getFbDatabase().getDatabaseDialect() == 1) {
+            return '"' + val.replace("\"", "\"\"") + '"';
+        }
+        return "'" + val.replace("'", "''") +  "'";
+    }
+
+    @Override
+    public final String enquoteNCharLiteral(String val) throws SQLException {
+        return enquoteLiteral(val);
+    }
+
+    // NOTE: This intentionally does not take case sensitivity into account
+    private static final Pattern SIMPLE_IDENTIFIER_PATTERN = Pattern.compile("\\p{Alpha}[\\p{Alnum}_$]*");
+
+    @Override
+    public final String enquoteIdentifier(String identifier, boolean alwaysDelimit) throws SQLException {
+        int len = identifier.length();
+        // See also comment in isSimpleIdentifier(String) regarding length check
+        if (len < 1 || len > getMetaData().getMaxColumnNameLength()) {
+            throw FbExceptionBuilder.forException(jb_invalidIdentifierLength).toSQLException();
+        }
+        if (!alwaysDelimit && isSimpleIdentifier(identifier)) {
+            return identifier;
+        }
+        QuoteStrategy quoteStrategy = getQuoteStrategy();
+        if (quoteStrategy == QuoteStrategy.NO_QUOTES /* dialect 1 */) {
+            throw FbExceptionBuilder.forException(jb_noDelimitedIdentifiersInDialect1).toSQLException();
+        }
+        if (identifier.matches("^\".+\"$")) {
+            // Delimited identifier: remove delimiter and unescape double quotes
+            identifier = identifier.substring(1, len - 1).replace("\"\"", "\"");
+        }
+        // If the identifier contains a null character, throw a SQLException
+        if (identifier.indexOf(0) != -1) {
+            throw FbExceptionBuilder.forException(jb_invalidIdentifierName).toSQLException();
+        }
+        // Delimit identifier and escape double quotes
+        return quoteStrategy.quoteObjectName(identifier);
+    }
+
+    @Override
+    public final boolean isSimpleIdentifier(String identifier) throws SQLException {
+        int len = identifier.length();
+        /* This length check can be incorrect for Firebird 3.0 and lower, if the identifier contains non-ASCII (limit is
+         * 31 characters UNICODE_FSS and 31 bytes).
+         * This length check can be incorrect for Firebird 4.0 and higher, if the identifier contains codepoints that
+         * require surrogate pairs.
+         * We accept those limitations. */
+        return len >= 1 && len <= getMetaData().getMaxColumnNameLength()
+                && SIMPLE_IDENTIFIER_PATTERN.matcher(identifier).matches()
+                && !isReservedWord(identifier);
+    }
+
+    private boolean isReservedWord(String word) throws SQLException {
+        return ((FirebirdDatabaseMetaData) getMetaData()).isReservedWord(word);
+    }
+
     /**
      * @see org.firebirdsql.gds.ng.FbAttachment#withLock()
      */

src/main/org/firebirdsql/jdbc/FBDatabaseMetaData.java

@@ -248,6 +248,11 @@ public String getSQLKeywords() throws SQLException {
         return versionMetaData.getSqlKeywords();
     }
 
+    @Override
+    public boolean isReservedWord(String word) {
+        return versionMetaData.isReservedWord(word);
+    }
+
     /**
      * {@inheritDoc}
      * <p>