Field(String tableName,
    String columnName,
    int jdbcType,
    int length) 
{
		this.tableName = tableName;
		this.name = columnName;
		this.length = length;
		this.sqlType = jdbcType;
		this.colFlag = 0;
		this.colDecimals = 0;
}

Constructor used by DatabaseMetaData methods.

 Field(String tableName,
    String columnName,
    int charsetIndex,
    int jdbcType,
    int length) 
{
		this.tableName = tableName;
		this.name = columnName;
		this.length = length;
		this.sqlType = jdbcType;
		this.colFlag = 0;
		this.colDecimals = 0;
		this.charsetIndex = charsetIndex;
		switch (this.sqlType) {
		case Types.BINARY:
		case Types.VARBINARY:
			this.colFlag |= 128;
			this.colFlag |= 16;
			break;
		}
}

Used by prepared statements to re-use result set data conversion methods when generating bound parmeter retrieval instance for statement interceptors.

Parameters:

tableName - not used

columnName - not used

charsetIndex - the MySQL collation/character set index

jdbcType - from java.sql.Types

length - length in characters or bytes (for BINARY data).

 Field(ConnectionImpl conn,
    byte[] buffer,
    int nameStart,
    int nameLength,
    int tableNameStart,
    int tableNameLength,
    int length,
    int mysqlType,
    short colFlag,
    int colDecimals) throws SQLException 
{
		this(conn, buffer, -1, -1, tableNameStart, tableNameLength, -1, -1,
				nameStart, nameLength, -1, -1, length, mysqlType, colFlag,
				colDecimals, -1, -1, NO_CHARSET_INFO);
}

Constructor used when communicating with pre 4.1 servers

 Field(ConnectionImpl conn,
    byte[] buffer,
    int databaseNameStart,
    int databaseNameLength,
    int tableNameStart,
    int tableNameLength,
    int originalTableNameStart,
    int originalTableNameLength,
    int nameStart,
    int nameLength,
    int originalColumnNameStart,
    int originalColumnNameLength,
    long length,
    int mysqlType,
    short colFlag,
    int colDecimals,
    int defaultValueStart,
    int defaultValueLength,
    int charsetIndex) throws SQLException 
{
		this.connection = conn;
		this.buffer = buffer;
		this.nameStart = nameStart;
		this.nameLength = nameLength;
		this.tableNameStart = tableNameStart;
		this.tableNameLength = tableNameLength;
		this.length = length;
		this.colFlag = colFlag;
		this.colDecimals = colDecimals;
		this.mysqlType = mysqlType;
		// 4.1 field info...
		this.databaseNameStart = databaseNameStart;
		this.databaseNameLength = databaseNameLength;
		this.originalTableNameStart = originalTableNameStart;
		this.originalTableNameLength = originalTableNameLength;
		this.originalColumnNameStart = originalColumnNameStart;
		this.originalColumnNameLength = originalColumnNameLength;
		this.defaultValueStart = defaultValueStart;
		this.defaultValueLength = defaultValueLength;
		// If we're not running 4.1 or newer, use the connection's
		// charset
		this.charsetIndex = charsetIndex;
		// Map MySqlTypes to java.sql Types
		this.sqlType = MysqlDefs.mysqlToJavaType(this.mysqlType);
        checkForImplicitTemporaryTable();
		// Re-map to 'real' blob type, if we're a BLOB
        boolean isFromFunction = this.originalTableNameLength == 0;
		if (this.mysqlType == MysqlDefs.FIELD_TYPE_BLOB) {
		    if (this.connection != null && this.connection.getBlobsAreStrings() ||
		            (this.connection.getFunctionsNeverReturnBlobs() && isFromFunction)) {
		        this.sqlType = Types.VARCHAR;
		        this.mysqlType = MysqlDefs.FIELD_TYPE_VARCHAR;
		    } else if (this.charsetIndex == 63 ||
					!this.connection.versionMeetsMinimum(4, 1, 0)) {
				if (this.connection.getUseBlobToStoreUTF8OutsideBMP() 
						&& shouldSetupForUtf8StringInBlob()) {
					setupForUtf8StringInBlob();
				} else {
					setBlobTypeBasedOnLength();
					this.sqlType = MysqlDefs.mysqlToJavaType(this.mysqlType);
				}
			} else {
				// *TEXT masquerading as blob
				this.mysqlType = MysqlDefs.FIELD_TYPE_VAR_STRING;
				this.sqlType = Types.LONGVARCHAR;
			}
		}
		if (this.sqlType == Types.TINYINT && this.length == 1
				&& this.connection.getTinyInt1isBit()) {
			// Adjust for pseudo-boolean
			if (conn.getTinyInt1isBit()) {
				if (conn.getTransformedBitIsBoolean()) {
					this.sqlType = Types.BOOLEAN;
				} else {
					this.sqlType = Types.BIT;
				}
			}
		}
		if (!isNativeNumericType() && !isNativeDateTimeType()) {
			this.charsetName = this.connection
				.getCharsetNameForIndex(this.charsetIndex);
			// Handle VARBINARY/BINARY (server doesn't have a different type
			// for this
			boolean isBinary = isBinary();
			if (this.connection.versionMeetsMinimum(4, 1, 0) &&
					this.mysqlType == MysqlDefs.FIELD_TYPE_VAR_STRING &&
					isBinary &&
					this.charsetIndex == 63) {
				if (this.connection != null && (this.connection.getFunctionsNeverReturnBlobs() && isFromFunction)) {
			        this.sqlType = Types.VARCHAR;
			        this.mysqlType = MysqlDefs.FIELD_TYPE_VARCHAR;
				} else if (this.isOpaqueBinary()) {
					this.sqlType = Types.VARBINARY;
				} 
			}
			if (this.connection.versionMeetsMinimum(4, 1, 0) &&
					this.mysqlType == MysqlDefs.FIELD_TYPE_STRING &&
					isBinary && this.charsetIndex == 63) {
				//
				// Okay, this is a hack, but there's currently no way
				// to easily distinguish something like DATE_FORMAT( ..)
				// from the "BINARY" column type, other than looking
				// at the original column name.
				//
				if (isOpaqueBinary() && !this.connection.getBlobsAreStrings()) {
					this.sqlType = Types.BINARY;
				}
			}
			if (this.mysqlType == MysqlDefs.FIELD_TYPE_BIT) {
				this.isSingleBit = (this.length == 0);
				if (this.connection != null && (this.connection.versionMeetsMinimum(5, 0, 21) ||
						this.connection.versionMeetsMinimum(5, 1, 10)) && this.length == 1) {
					this.isSingleBit = true;
				}
				if (this.isSingleBit) {
					this.sqlType = Types.BIT;
				} else {
					this.sqlType = Types.VARBINARY;
					this.colFlag |= 128; // we need to pretend this is a full
					this.colFlag |= 16; // binary blob
					isBinary = true;
				}
			}
			//
			// Handle TEXT type (special case), Fix proposed by Peter McKeown
			//
			if ((this.sqlType == java.sql.Types.LONGVARBINARY) && !isBinary) {
				this.sqlType = java.sql.Types.LONGVARCHAR;
			} else if ((this.sqlType == java.sql.Types.VARBINARY) && !isBinary) {
				this.sqlType = java.sql.Types.VARCHAR;
			}
		} else {
			this.charsetName = "US-ASCII";
		}
		//
		// Handle odd values for 'M' for floating point/decimal numbers
		//
		if (!isUnsigned()) {
			switch (this.mysqlType) {
			case MysqlDefs.FIELD_TYPE_DECIMAL:
			case MysqlDefs.FIELD_TYPE_NEW_DECIMAL:
				this.precisionAdjustFactor = -1;
				break;
			case MysqlDefs.FIELD_TYPE_DOUBLE:
			case MysqlDefs.FIELD_TYPE_FLOAT:
				this.precisionAdjustFactor = 1;
				break;
			}
		} else {
			switch (this.mysqlType) {
			case MysqlDefs.FIELD_TYPE_DOUBLE:
			case MysqlDefs.FIELD_TYPE_FLOAT:
				this.precisionAdjustFactor = 1;
				break;
			}
		}
}

Constructor used when communicating with 4.1 and newer servers

 public String getCharacterSet() throws SQLException 
{
		return this.charsetName;
}

Returns the character set (if known) for this field.

 public synchronized String getCollation() throws SQLException 
{
		if (this.collationName == null) {
			if (this.connection != null) {
				if (this.connection.versionMeetsMinimum(4, 1, 0)) {
					if (this.connection.getUseDynamicCharsetInfo()) {
						java.sql.DatabaseMetaData dbmd = this.connection
								.getMetaData();
						String quotedIdStr = dbmd.getIdentifierQuoteString();
						if (" ".equals(quotedIdStr)) { //$NON-NLS-1$
							quotedIdStr = ""; //$NON-NLS-1$
						}
						String csCatalogName = getDatabaseName();
						String csTableName = getOriginalTableName();
						String csColumnName = getOriginalName();
						if (csCatalogName != null && csCatalogName.length() != 0
								&& csTableName != null && csTableName.length() != 0
								&& csColumnName != null
								&& csColumnName.length() != 0) {
							StringBuffer queryBuf = new StringBuffer(csCatalogName
									.length()
									+ csTableName.length() + 28);
							queryBuf.append("SHOW FULL COLUMNS FROM "); //$NON-NLS-1$
							queryBuf.append(quotedIdStr);
							queryBuf.append(csCatalogName);
							queryBuf.append(quotedIdStr);
							queryBuf.append("."); //$NON-NLS-1$
							queryBuf.append(quotedIdStr);
							queryBuf.append(csTableName);
							queryBuf.append(quotedIdStr);
							java.sql.Statement collationStmt = null;
							java.sql.ResultSet collationRs = null;
							try {
								collationStmt = this.connection.createStatement();
								collationRs = collationStmt.executeQuery(queryBuf
										.toString());
								while (collationRs.next()) {
									if (csColumnName.equals(collationRs
											.getString("Field"))) { //$NON-NLS-1$
										this.collationName = collationRs
												.getString("Collation"); //$NON-NLS-1$
										break;
									}
								}
							} finally {
								if (collationRs != null) {
									collationRs.close();
									collationRs = null;
								}
								if (collationStmt != null) {
									collationStmt.close();
									collationStmt = null;
								}
							}
						}
					} else {
						this.collationName = CharsetMapping.INDEX_TO_COLLATION[charsetIndex];
					}
				}
			}
		}
		return this.collationName;
}

 public String getColumnLabel() throws SQLException 
{
		return getName(); // column name if not aliased, alias if used
}

 public String getDatabaseName() throws SQLException 
{
		if ((this.databaseName == null) && (this.databaseNameStart != -1)
				&& (this.databaseNameLength != -1)) {
			this.databaseName = getStringFromBytes(this.databaseNameStart,
					this.databaseNameLength);
		}
		return this.databaseName;
}

DOCUMENT ME!

 int getDecimals() 
{
		return this.colDecimals;
}

 public String getFullName() throws SQLException 
{
		if (this.fullName == null) {
			StringBuffer fullNameBuf = new StringBuffer(getTableName().length()
					+ 1 + getName().length());
			fullNameBuf.append(this.tableName);
			// much faster to append a char than a String
			fullNameBuf.append('.');
			fullNameBuf.append(this.name);
			this.fullName = fullNameBuf.toString();
			fullNameBuf = null;
		}
		return this.fullName;
}

DOCUMENT ME!

 public String getFullOriginalName() throws SQLException 
{
		getOriginalName();
		if (this.originalColumnName == null) {
			return null; // we don't have this information
		}
		if (this.fullName == null) {
			StringBuffer fullOriginalNameBuf = new StringBuffer(
					getOriginalTableName().length() + 1
							+ getOriginalName().length());
			fullOriginalNameBuf.append(this.originalTableName);
			// much faster to append a char than a String
			fullOriginalNameBuf.append('.');
			fullOriginalNameBuf.append(this.originalColumnName);
			this.fullOriginalName = fullOriginalNameBuf.toString();
			fullOriginalNameBuf = null;
		}
		return this.fullOriginalName;
}

DOCUMENT ME!

 public long getLength() 
{
		return this.length;
}

DOCUMENT ME!

 public synchronized int getMaxBytesPerCharacter() throws SQLException 
{
		if (this.maxBytesPerChar == 0) {
			this.maxBytesPerChar = this.connection.getMaxBytesPerChar(getCharacterSet());
		}
		return this.maxBytesPerChar;
}

 public int getMysqlType() 
{
		return this.mysqlType;
}

DOCUMENT ME!

 public String getName() throws SQLException 
{
		if (this.name == null) {
			this.name = getStringFromBytes(this.nameStart, this.nameLength);
		}
		return this.name;
}

DOCUMENT ME!

 public String getNameNoAliases() throws SQLException 
{
		if (this.useOldNameMetadata) {
			return getName();
		}
		if (this.connection != null &&
				this.connection.versionMeetsMinimum(4, 1, 0)) {
			return getOriginalName();
		}
		return getName();
}

 public String getOriginalName() throws SQLException 
{
		if ((this.originalColumnName == null)
				&& (this.originalColumnNameStart != -1)
				&& (this.originalColumnNameLength != -1)) {
			this.originalColumnName = getStringFromBytes(
					this.originalColumnNameStart, this.originalColumnNameLength);
		}
		return this.originalColumnName;
}

DOCUMENT ME!

 public String getOriginalTableName() throws SQLException 
{
		if ((this.originalTableName == null)
				&& (this.originalTableNameStart != -1)
				&& (this.originalTableNameLength != -1)) {
			this.originalTableName = getStringFromBytes(
					this.originalTableNameStart, this.originalTableNameLength);
		}
		return this.originalTableName;
}

DOCUMENT ME!

 public int getPrecisionAdjustFactor() 
{
		return this.precisionAdjustFactor;
}

Returns amount of correction that should be applied to the precision value. Different versions of MySQL report different precision values.

 public int getSQLType() 
{
		return this.sqlType;
}

DOCUMENT ME!

 public String getTable() throws SQLException 
{
		return getTableName();
}

DOCUMENT ME!

 public String getTableName() throws SQLException 
{
		if (this.tableName == null) {
			this.tableName = getStringFromBytes(this.tableNameStart,
					this.tableNameLength);
		}
		return this.tableName;
}

DOCUMENT ME!

 public String getTableNameNoAliases() throws SQLException 
{
		if (this.connection.versionMeetsMinimum(4, 1, 0)) {
			return getOriginalTableName();
		}
		return getTableName(); // pre-4.1, no aliases returned
}

 public boolean isAutoIncrement() 
{
		return ((this.colFlag & AUTO_INCREMENT_FLAG)  > 0);
}

DOCUMENT ME!

 public boolean isBinary() 
{
		return ((this.colFlag & 128)  > 0);
}

DOCUMENT ME!

 public boolean isBlob() 
{
		return ((this.colFlag & 16)  > 0);
}

DOCUMENT ME!

 public boolean isMultipleKey() 
{
		return ((this.colFlag & 8)  > 0);
}

DOCUMENT ME!

 boolean isNotNull() 
{
		return ((this.colFlag & 1)  > 0);
}

 boolean isOpaqueBinary() throws SQLException 
{
		//
		// Detect CHAR(n) CHARACTER SET BINARY which is a synonym for
		// fixed-length binary types
		//
		if (this.charsetIndex == 63 && isBinary()
				&& (this.getMysqlType() == MysqlDefs.FIELD_TYPE_STRING ||
				this.getMysqlType() == MysqlDefs.FIELD_TYPE_VAR_STRING)) {
			if (this.originalTableNameLength == 0 && (
					this.connection != null && !this.connection.versionMeetsMinimum(5, 0, 25))) {
				return false; // Probably from function
			}
			// Okay, queries resolved by temp tables also have this 'signature',
			// check for that
			return !isImplicitTemporaryTable();
		}
		return (this.connection.versionMeetsMinimum(4, 1, 0) && "binary"
				.equalsIgnoreCase(getCharacterSet()));
}

 public boolean isPrimaryKey() 
{
		return ((this.colFlag & 2)  > 0);
}

DOCUMENT ME!

 boolean isReadOnly() throws SQLException 
{
		if (this.connection.versionMeetsMinimum(4, 1, 0)) {
			String orgColumnName = getOriginalName();
			String orgTableName = getOriginalTableName();
			return !(orgColumnName != null && orgColumnName.length()  > 0
					&& orgTableName != null && orgTableName.length()  > 0);
		}
		return false; // we can't tell definitively in this case.
}

Is this field _definitely_ not writable?

 protected boolean isSingleBit() 
{
		return this.isSingleBit;
}

 public boolean isUniqueKey() 
{
		return ((this.colFlag & 4)  > 0);
}

DOCUMENT ME!

 public boolean isUnsigned() 
{
		return ((this.colFlag & 32)  > 0);
}

DOCUMENT ME!

 public boolean isZeroFill() 
{
		return ((this.colFlag & 64)  > 0);
}

DOCUMENT ME!

 public  void setCharacterSet(String javaEncodingName) throws SQLException 
{
		this.charsetName = javaEncodingName;
		this.charsetIndex = CharsetMapping
				.getCharsetIndexForMysqlEncodingName(javaEncodingName);
}

 public  void setConnection(ConnectionImpl conn) 
{
		this.connection = conn;
		if (this.charsetName == null || this.charsetIndex == 0) {
			this.charsetName = this.connection.getEncoding();
		}
}

DOCUMENT ME!

  void setMysqlType(int type) 
{
		this.mysqlType = type;
		this.sqlType = MysqlDefs.mysqlToJavaType(this.mysqlType);
}

 public  void setUnsigned() 
{
		this.colFlag |= 32;
}

 protected  void setUseOldNameMetadata(boolean useOldNameMetadata) 
{
		this.useOldNameMetadata = useOldNameMetadata;
}

 public String toString() 
{
		try {
			StringBuffer asString = new StringBuffer();
			asString.append(super.toString());
			asString.append("[");
			asString.append("catalog=");
			asString.append(this.getDatabaseName());
			asString.append(",tableName=");
			asString.append(this.getTableName());
			asString.append(",originalTableName=");
			asString.append(this.getOriginalTableName());
			asString.append(",columnName=");
			asString.append(this.getName());
			asString.append(",originalColumnName=");
			asString.append(this.getOriginalName());
			asString.append(",mysqlType=");
			asString.append(getMysqlType());
			asString.append("(");
			asString.append(MysqlDefs.typeToName(getMysqlType()));
			asString.append(")");
			asString.append(",flags=");
			if (isAutoIncrement()) {
				asString.append(" AUTO_INCREMENT");
			}
			if (isPrimaryKey()) {
				asString.append(" PRIMARY_KEY");
			}
			if (isUniqueKey()) {
				asString.append(" UNIQUE_KEY");
			}
			if (isBinary()) {
				asString.append(" BINARY");
			}
			if (isBlob()) {
				asString.append(" BLOB");
			}
			if (isMultipleKey()) {
				asString.append(" MULTI_KEY");
			}
			if (isUnsigned()) {
				asString.append(" UNSIGNED");
			}
			if (isZeroFill()) {
				asString.append(" ZEROFILL");
			}
			asString.append(", charsetIndex=");
			asString.append(this.charsetIndex);
			asString.append(", charsetName=");
			asString.append(this.charsetName);
			//if (this.buffer != null) {
			//	asString.append("\n\nData as received from server:\n\n");
			//	asString.append(StringUtils.dumpAsHex(this.buffer,
			//			this.buffer.length));
			//}
			asString.append("]");
			return asString.toString();
		} catch (Throwable t) {
			return super.toString();
		}
}