JDBC 驱动程序概述
JDBC 驱动程序的新增功能
JDBC 驱动程序的系统要求
使用 JDBC 驱动程序
了解 J2EE 支持
部署 JDBC 驱动程序
查找 JDBC 驱动程序的其他信息
通过 JDBC 驱动程序连接到 SQL Server
创建连接 URL
设置连接属性
设置数据源属性
使用连接
使用连接池
使用数据库镜像 (JDBC)
了解 JDBC 驱动程序数据类型
使用基本数据类型
使用高级数据类型
了解数据类型的差异
了解数据类型转换
通过 JDBC 驱动程序使用语句
使用 SQL 语句
使用不带参数的 SQL 语句
使用带参数的 SQL 语句
使用 SQL 语句修改数据库对象
使用 SQL 语句修改数据
使用带有存储过程的语句
使用不带参数的存储过程
使用带有输入参数的存储过程
使用带有输出参数的存储过程
使用带有返回状态的存储过程
使用带有更新计数的存储过程
使用多个结果集
使用 SQL 转义序列
使用自动生成的键
执行批处理操作
处理复杂语句
通过 JDBC 驱动程序管理结果集
了解游标类型
了解并发控制
了解行锁定
通过 JDBC 驱动程序执行事务
了解事务
了解 XA 事务
了解隔离级别
使用保存点
使用保持能力
使用 JDBC 驱动程序处理元数据
使用数据库元数据
使用结果集元数据
使用参数元数据
保护 JDBC Driver 应用程序
保护连接字符串
验证用户输入
应用程序安全性
使用 SSL 加密
了解 SSL 支持
使用 SSL 加密进行连接
为 SSL 加密配置客户端
借助 JDBC 驱动程序提高性能和可靠性
不使用时关闭对象
管理事务大小
使用语句和结果集
使用自适应缓冲
诊断与 JDBC 驱动程序有关的问题
处理错误
获取驱动程序版本
跟踪驱动程序操作
连接性疑难解答
JDBC 驱动程序的国际功能
示例 JDBC 驱动程序应用程序
连接和检索数据
连接 URL 示例
数据源示例
使用数据类型 (JDBC)
基本数据类型示例
使用结果集
结果集数据检索示例
结果集数据修改示例
结果集数据缓存示例
使用自适应缓冲
设置自适应缓冲示例
在存储过程中使用自适应缓冲的示例
JDBC Driver API Reference
SQLServerBlob Class
SQLServerBlob Members
SQLServerBlob Constructor (SQLServerConnection, byte[])
getBinaryStream Method (SQLServerBlob)
getBytes Method (SQLServerBlob)
length Method (SQLServerBlob)
position Method (java.sql.Blob, long)
position Method (byte[], long)
setBinaryStream Method (SQLServerBlob)
setBytes Method (long, byte[])
setBytes Method (long, byte[], int, int)
truncate Method (SQLServerBlob)
SQLServerCallableStatement Class
SQLServerCallableStatement Members
getArray Method (int)
getArray Method (java.lang.String)
getAsciiStream (int)
getAsciiStream (java.lang.String)
getBigDecimal Method (int)
getBigDecimal Method (int, int)
getBigDecimal Method (java.lang.String)
getBigDecimal Method (java.lang.String, int)
getBinaryStream (int)
getBinaryStream (java.lang.String)
getBlob Method (int)
getBlob Method (java.lang.String)
getBoolean Method (int)
getBoolean Method (java.lang.String)
getByte Method (int)
getByte Method (java.lang.String)
getBytes Method (int)
getBytes Method (java.lang.String)
getCharacterStream (int)
getCharacterStream (java.lang.String)
getClob Method (int)
getClob Method (java.lang.String)
getDate Method (int)
getDate Method (int, java.util.Calendar)
getDate Method (java.lang.String)
getDate Method (java.lang.String, java.util.Calendar)
getDouble Method (int)
getDouble Method (java.lang.String)
getFloat Method (int)
getFloat Method (java.lang.String)
getInt Method (int)
getInt Method (java.lang.String)
getLong Method (int)
getLong Method (java.lang.String)
getObject Method (int)
getObject Method (int, java.util.Map)
getObject Method (java.lang.String)
getObject Method (java.lang.String, java.util.Map)
getRef Method (int)
getRef Method (java.lang.String)
getShort Method (int)
getShort Method (java.lang.String)
getString Method (int)
getString Method (java.lang.String)
getTime Method (int)
getTime Method (int, java.util.Calendar)
getTime Method (java.lang.String)
getTime Method (java.lang.String, java.util.Calendar)
getTimestamp Method (int)
getTimestamp Method (int, java.util.Calendar)
getTimestamp Method (java.lang.String)
getTimestamp Method (java.lang.String, java.util.Calendar)
getURL Method (int)
getURL Method (java.lang.String)
registerOutParameter Method (int, int)
registerOutParameter Method (int, int, int)
registerOutParameter Method (int, int, java.lang.String)
registerOutParameter Method (java.lang.String, int)
registerOutParameter Method (java.lang.String, int, int)
registerOutParameter Method (java.lang.String, int, java.lang.String)
setAsciiStream Method (SQLServerCallableStatement)
setBigDecimal Method (SQLServerCallableStatement)
setBinaryStream Method (SQLServerCallableStatement)
setBoolean Method (SQLServerCallableStatement)
setByte Method (SQLServerCallableStatement)
setBytes Method (SQLServerCallableStatement)
setCharacterStream Method (SQLServerCallableStatement)
setDate Method (java.lang.String, java.sql.Date)
setDate Method (java.lang.String, java.sql.Date, java.util.Calendar)
setDouble Method (SQLServerCallableStatement)
setFloat Method (SQLServerCallableStatement)
setInt Method (SQLServerCallableStatement)
setLong Method (SQLServerCallableStatement)
setNull Method (java.lang.String, int)
setNull Method (java.lang.String, int, java.lang.String)
setObject Method (java.lang.String, java.lang.Object)
setObject Method (java.lang.String, java.lang.Object, int)
setObject Method (java.lang.String, java.lang.Object, int, int)
setShort Method (SQLServerCallableStatement)
setString Method (SQLServerCallableStatement)
setTime Method (java.lang.String, java.sql.Time)
setTime Method (java.lang.String, java.sql.Time, java.util.Calendar)
setTimestamp Method (java.lang.String, java.sql.Timestamp)
setTimestamp Method (java.lang.String, java.sql.Timestamp, java.util.Calendar)
setURL Method (SQLServerCallableStatement)
wasNull Method (SQLServerCallableStatement)
SQLServerClob Class
SQLServerClob Members
SQLServerClob Constructor (SQLServerConnection, java.lang.String)
getAsciiStream Method (SQLServerClob)
getCharacterStream Method (SQLServerClob)
getSubString Method (SQLServerClob)
length Method (SQLServerClob)
position Method (java.sql.Clob, long)
position Method (java.lang.String, long)
setAsciiStream Method (SQLServerClob)
setCharacterStream Method (SQLServerClob)
setString Method (long, java.lang.String)
setString Method (long, java.lang.String, int, int)
truncate Method (SQLServerClob)
SQLServerConnection Class
SQLServerConnection Members
clearWarnings Method (SQLServerConnection)
close Method (SQLServerConnection)
commit Method (SQLServerConnection)
createStatement Method ()
createStatement Method (int, int)
createStatement Method (int, int, int)
getAutoCommit Method (SQLServerConnection)
getCatalog Method (SQLServerConnection)
getHoldability Method (SQLServerConnection)
getMetaData Method (SQLServerConnection)
getTransactionIsolation Method (SQLServerConnection)
getTypeMap Method (SQLServerConnection)
getWarnings Method (SQLServerConnection)
isClosed Method (SQLServerConnection)
isReadOnly Method (SQLServerConnection)
nativeSQL Method (SQLServerConnection)
prepareCall Method (java.lang.String)
prepareCall Method (java.lang.String, int, int)
prepareCall Method (java.lang.String, int, int, int)
prepareStatement Method (java.lang.String)
prepareStatement Method (java.lang.String, int)
prepareStatement Method (java.lang.String, int[])
prepareStatement Method (java.lang.String, int, int)
prepareStatement Method (java.lang.String, int, int, int)
prepareStatement Method (java.lang.String, java.lang.String[])
releaseSavepoint Method (SQLServerConnection)
rollback Method ()
rollback Method (java.sql.Savepoint)
setAutoCommit Method (SQLServerConnection)
setCatalog Method (SQLServerConnection)
setHoldability Method (SQLServerConnection)
setReadOnly Method (SQLServerConnection)
setSavepoint Method ()
setSavepoint Method (java.lang.String)
setTransactionIsolation Method (SQLServerConnection)
setTypeMap Method (SQLServerConnection)
TRANSACTION_SNAPSHOT Field (SQLServerConnection)
SQLServerConnectionPoolDataSource Class
SQLServerConnectionPoolDataSource Members
SQLServerConnectionPoolDataSource Constructor ()
getPooledConnection Method ()
getPooledConnection Method (java.lang.String, java.lang.String)
getReference Method (SQLServerConnectionPoolDataSource)
SQLServerDatabaseMetaData Class
SQLServerDatabaseMetaData Members
allProceduresAreCallable Method (SQLServerDatabaseMetaData)
allTablesAreSelectable Method (SQLServerDatabaseMetaData)
dataDefinitionCausesTransactionCommit Method (SQLServerDatabaseMetaData)
dataDefinitionIgnoredInTransactions Method (SQLServerDatabaseMetaData)
deletesAreDetected Method (SQLServerDatabaseMetaData)
doesMaxRowSizeIncludeBlobs Method (SQLServerDatabaseMetaData)
getAttributes Method (SQLServerDatabaseMetaData)
getBestRowIdentifier Method (SQLServerDatabaseMetaData)
getCatalogs Method (SQLServerDatabaseMetaData)
getCatalogSeparator Method (SQLServerDatabaseMetaData)
getCatalogTerm Method (SQLServerDatabaseMetaData)
getColumnPrivileges Method (SQLServerDatabaseMetaData)
getColumns Method (SQLServerDatabaseMetaData)
getConnection Method (SQLServerDatabaseMetaData)
getCrossReference Method (SQLServerDatabaseMetaData)
getDatabaseMajorVersion Method (SQLServerDatabaseMetaData)
getDatabaseMinorVersion Method (SQLServerDatabaseMetaData)
getDatabaseProductName Method (SQLServerDatabaseMetaData)
getDatabaseProductVersion Method (SQLServerDatabaseMetaData)
getDefaultTransactionIsolation Method (SQLServerDatabaseMetaData)
getDriverMajorVersion Method (SQLServerDatabaseMetaData)
getDriverMinorVersion Method (SQLServerDatabaseMetaData)
getDriverName Method (SQLServerDatabaseMetaData)
getDriverVersion Method (SQLServerDatabaseMetaData)
getExportedKeys Method (SQLServerDatabaseMetaData)
getExtraNameCharacters Method (SQLServerDatabaseMetaData)
getIdentifierQuoteString Method (SQLServerDatabaseMetaData)
getImportedKeys Method (SQLServerDatabaseMetaData)
getIndexInfo Method (SQLServerDatabaseMetaData)
getJDBCMajorVersion Method (SQLServerDatabaseMetaData)
getJDBCMinorVersion Method (SQLServerDatabaseMetaData)
getMaxBinaryLiteralLength Method (SQLServerDatabaseMetaData)
getMaxCatalogNameLength Method (SQLServerDatabaseMetaData)
getMaxCharLiteralLength Method (SQLServerDatabaseMetaData)
getMaxColumnNameLength Method (SQLServerDatabaseMetaData)
getMaxColumnsInGroupBy Method (SQLServerDatabaseMetaData)
getMaxColumnsInIndex Method (SQLServerDatabaseMetaData)
getMaxColumnsInOrderBy Method (SQLServerDatabaseMetaData)
getMaxColumnsInSelect Method (SQLServerDatabaseMetaData)
getMaxColumnsInTable Method (SQLServerDatabaseMetaData)
getMaxConnections Method (SQLServerDatabaseMetaData)
getMaxCursorNameLength Method (SQLServerDatabaseMetaData)
getMaxIndexLength Method (SQLServerDatabaseMetaData)
getMaxProcedureNameLength Method (SQLServerDatabaseMetaData)
getMaxRowSize Method (SQLServerDatabaseMetaData)
getMaxSchemaNameLength Method (SQLServerDatabaseMetaData)
getMaxStatementLength Method (SQLServerDatabaseMetaData)
getMaxStatements Method (SQLServerDatabaseMetaData)
getMaxTableNameLength Method (SQLServerDatabaseMetaData)
getMaxTablesInSelect Method (SQLServerDatabaseMetaData)
getMaxUserNameLength Method (SQLServerDatabaseMetaData)
getNumericFunctions Method (SQLServerDatabaseMetaData)
getPrimaryKeys Method (SQLServerDatabaseMetaData)
getProcedureColumns Method (SQLServerDatabaseMetaData)
getProcedures Method (SQLServerDatabaseMetaData)
getProcedureTerm Method (SQLServerDatabaseMetaData)
getResultSetHoldability Method (SQLServerDatabaseMetaData)
getSchemas Method (SQLServerDatabaseMetaData)
getSchemaTerm Method (SQLServerDatabaseMetaData)
getSearchStringEscape Method (SQLServerDatabaseMetaData)
getSQLKeywords Method (SQLServerDatabaseMetaData)
getSQLStateType Method (SQLServerDatabaseMetaData)
getStringFunctions Method (SQLServerDatabaseMetaData)
getSuperTables Method (SQLServerDatabaseMetaData)
getSuperTypes Method (SQLServerDatabaseMetaData)
getSystemFunctions Method (SQLServerDatabaseMetaData)
getTablePrivileges Method (SQLServerDatabaseMetaData)
getTables Method (SQLServerDatabaseMetaData)
getTableTypes Method (SQLServerDatabaseMetaData)
getTimeDateFunctions Method (SQLServerDatabaseMetaData)
getTypeInfo Method (SQLServerDatabaseMetaData)
getUDTs Method (SQLServerDatabaseMetaData)
getURL Method (SQLServerDatabaseMetaData)
getUserName Method (SQLServerDatabaseMetaData)
getVersionColumns Method (SQLServerDatabaseMetaData)
insertsAreDetected Method (SQLServerDatabaseMetaData)
isCatalogAtStart Method (SQLServerDatabaseMetaData)
isReadOnly Method (SQLServerDatabaseMetaData)
locatorsUpdateCopy Method (SQLServerDatabaseMetaData)
nullPlusNonNullIsNull Method (SQLServerDatabaseMetaData)
nullsAreSortedAtEnd Method (SQLServerDatabaseMetaData)
nullsAreSortedAtStart Method (SQLServerDatabaseMetaData)
nullsAreSortedHigh Method (SQLServerDatabaseMetaData)
nullsAreSortedLow Method (SQLServerDatabaseMetaData)
othersDeletesAreVisible Method (SQLServerDatabaseMetaData)
othersInsertsAreVisible Method (SQLServerDatabaseMetaData)
othersUpdatesAreVisible Method (SQLServerDatabaseMetaData)
ownDeletesAreVisible Method (SQLServerDatabaseMetaData)
ownInsertsAreVisible Method (SQLServerDatabaseMetaData)
ownUpdatesAreVisible Method (SQLServerDatabaseMetaData)
storesLowerCaseIdentifiers Method (SQLServerDatabaseMetaData)
storesLowerCaseQuotedIdentifiers Method (SQLServerDatabaseMetaData)
storesMixedCaseIdentifiers Method (SQLServerDatabaseMetaData)
storesMixedCaseQuotedIdentifiers Method (SQLServerDatabaseMetaData)
storesUpperCaseIdentifiers Method (SQLServerDatabaseMetaData)
storesUpperCaseQuotedIdentifiers Method (SQLServerDatabaseMetaData)
supportsAlterTableWithAddColumn Method (SQLServerDatabaseMetaData)
supportsAlterTableWithDropColumn Method (SQLServerDatabaseMetaData)
supportsANSI92EntryLevelSQL Method (SQLServerDatabaseMetaData)
supportsANSI92FullSQL Method (SQLServerDatabaseMetaData)
supportsANSI92IntermediateSQL Method (SQLServerDatabaseMetaData)
supportsBatchUpdates Method (SQLServerDatabaseMetaData)
supportsCatalogsInDataManipulation Method (SQLServerDatabaseMetaData)
supportsCatalogsInIndexDefinitions Method (SQLServerDatabaseMetaData)
supportsCatalogsInPrivilegeDefinitions Method (SQLServerDatabaseMetaData)
supportsCatalogsInProcedureCalls Method (SQLServerDatabaseMetaData)
supportsCatalogsInTableDefinitions Method (SQLServerDatabaseMetaData)
supportsColumnAliasing Method (SQLServerDatabaseMetaData)
supportsConvert Method ()
supportsConvert Method (int, int)
supportsCoreSQLGrammar Method (SQLServerDatabaseMetaData)
supportsCorrelatedSubqueries Method (SQLServerDatabaseMetaData)
supportsDataDefinitionAndDataManipulationTransactions Method (SQLServerDatabaseMetaData)
supportsDataManipulationTransactionsOnly Method (SQLServerDatabaseMetaData)
supportsDifferentTableCorrelationNames Method (SQLServerDatabaseMetaData)
supportsExpressionsInOrderBy Method (SQLServerDatabaseMetaData)
supportsExtendedSQLGrammar Method (SQLServerDatabaseMetaData)
supportsFullOuterJoins Method (SQLServerDatabaseMetaData)
supportsGetGeneratedKeys Method (SQLServerDatabaseMetaData)
supportsGroupBy Method (SQLServerDatabaseMetaData)
supportsGroupByBeyondSelect Method (SQLServerDatabaseMetaData)
supportsGroupByUnrelated Method (SQLServerDatabaseMetaData)
supportsIntegrityEnhancementFacility Method (SQLServerDatabaseMetaData)
supportsLikeEscapeClause Method (SQLServerDatabaseMetaData)
supportsLimitedOuterJoins Method (SQLServerDatabaseMetaData)
supportsMinimumSQLGrammar Method (SQLServerDatabaseMetaData)
supportsMixedCaseIdentifiers Method (SQLServerDatabaseMetaData)
supportsMixedCaseQuotedIdentifiers Method (SQLServerDatabaseMetaData)
supportsMultipleOpenResults Method (SQLServerDatabaseMetaData)
supportsMultipleResultSets Method (SQLServerDatabaseMetaData)
supportsMultipleTransactions Method (SQLServerDatabaseMetaData)
supportsNamedParameters Method (SQLServerDatabaseMetaData)
supportsNonNullableColumns Method (SQLServerDatabaseMetaData)
supportsOpenCursorsAcrossCommit Method (SQLServerDatabaseMetaData)
supportsOpenCursorsAcrossRollback Method (SQLServerDatabaseMetaData)
supportsOpenStatementsAcrossCommit Method (SQLServerDatabaseMetaData)
supportsOpenStatementsAcrossRollback Method (SQLServerDatabaseMetaData)
supportsOrderByUnrelated Method (SQLServerDatabaseMetaData)
supportsOuterJoins Method (SQLServerDatabaseMetaData)
supportsPositionedDelete Method (SQLServerDatabaseMetaData)
supportsPositionedUpdate Method (SQLServerDatabaseMetaData)
supportsResultSetConcurrency Method (SQLServerDatabaseMetaData)
supportsResultSetHoldability Method (SQLServerDatabaseMetaData)
supportsResultSetType Method (SQLServerDatabaseMetaData)
supportsSavepoints Method (SQLServerDatabaseMetaData)
supportsSchemasInDataManipulation Method (SQLServerDatabaseMetaData)
supportsSchemasInIndexDefinitions Method (SQLServerDatabaseMetaData)
supportsSchemasInPrivilegeDefinitions Method (SQLServerDatabaseMetaData)
supportsSchemasInProcedureCalls Method (SQLServerDatabaseMetaData)
supportsSchemasInTableDefinitions Method (SQLServerDatabaseMetaData)
supportsSelectForUpdate Method (SQLServerDatabaseMetaData)
supportsStatementPooling Method (SQLServerDatabaseMetaData)
supportsStoredProcedures Method (SQLServerDatabaseMetaData)
supportsSubqueriesInComparisons Method (SQLServerDatabaseMetaData)
supportsSubqueriesInExists Method (SQLServerDatabaseMetaData)
supportsSubqueriesInIns Method (SQLServerDatabaseMetaData)
supportsSubqueriesInQuantifieds Method (SQLServerDatabaseMetaData)
supportsTableCorrelationNames Method (SQLServerDatabaseMetaData)
supportsTransactionIsolationLevel Method (SQLServerDatabaseMetaData)
supportsTransactions Method (SQLServerDatabaseMetaData)
supportsUnion Method (SQLServerDatabaseMetaData)
supportsUnionAll Method (SQLServerDatabaseMetaData)
updatesAreDetected Method (SQLServerDatabaseMetaData)
usesLocalFilePerTable Method (SQLServerDatabaseMetaData)
usesLocalFiles Method (SQLServerDatabaseMetaData)
SQLServerDataSource Class
SQLServerDataSource Members
SQLServerDataSource Constructor ()
getApplicationName Method (SQLServerDataSource)
getConnection Method ()
getConnection Method (java.lang.String, java.lang.String)
getDatabaseName Method (SQLServerDataSource)
getDescription Method (SQLServerDataSource)
getEncrypt Method (SQLServerDataSource)
getFailoverPartner Method (SQLServerDataSource)
getHostNameInCertificate Method (SQLServerDataSource)
getInstanceName Method (SQLServerDataSource)
getLastUpdateCount Method (SQLServerDataSource)
getLockTimeout Method (SQLServerDataSource)
getLoginTimeout Method (SQLServerDataSource)
getLogWriter Method (SQLServerDataSource)
getPacketSize Method (SQLServerDataSource)
getPortNumber Method (SQLServerDataSource)
getReference Method (SQLServerDataSource)
getResponseBuffering Method (SQLServerDataSource)
getSelectMethod Method (SQLServerDataSource)
getSendStringParametersAsUnicode Method (SQLServerDataSource)
getServerName Method (SQLServerDataSource)
getTrustServerCertificate Method (SQLServerDataSource)
getTrustStore Method (SQLServerDataSource)
getURL Method (SQLServerDataSource)
getUser Method (SQLServerDataSource)
getWorkstationID Method (SQLServerDataSource)
getXopenStates Method (SQLServerDataSource)
setApplicationName Method (SQLServerDataSource)
setDatabaseName Method (SQLServerDataSource)
setDescription Method (SQLServerDataSource)
setEncrypt Method (SQLServerDataSource)
setFailoverPartner Method (SQLServerDataSource)
setHostNameInCertificate Method (SQLServerDataSource)
setInstanceName Method (SQLServerDataSource)
setIntegratedSecurity Method (SQLServerDataSource)
setLastUpdateCount Method (SQLServerDataSource)
setLockTimeout Method (SQLServerDataSource)
setLoginTimeout Method (SQLServerDataSource)
setLogWriter Method (SQLServerDataSource)
setPacketSize Method (SQLServerDataSource)
setPassword Method (SQLServerDataSource)
setPortNumber Method (SQLServerDataSource)
setSelectMethod Method (SQLServerDataSource)
setResponseBuffering Method (SQLServerDataSource)
setSendStringParametersAsUnicode Method (SQLServerDataSource)
setServerName Method (SQLServerDataSource)
setTrustServerCertificate Method (SQLServerDataSource)
setTrustStore Method (SQLServerDataSource)
setTrustStorePassword Method (SQLServerDataSource)
setURL Method (SQLServerDataSource)
setUser Method (SQLServerDataSource)
setWorkstationID Method (SQLServerDataSource)
setXopenStates Method (SQLServerDataSource)
SQLServerDataSourceObjectFactory Class
SQLServerDataSourceObjectFactory Members
SQLServerDataSourceObjectFactory Constructor ()
getObjectInstance Method (SQLServerDataSourceObjectFactory)
SQLServerDriver Class
SQLServerDriver Members
SQLServerDriver Constructor ()
acceptsURL Method (SQLServerDriver)
connect Method (SQLServerDriver)
getMajorVersion Method (SQLServerDriver)
getMinorVersion Method (SQLServerDriver)
getPropertyInfo Method (SQLServerDriver)
jdbcCompliant Method (SQLServerDriver)
SQLServerException Class
SQLServerException Members
SQLServerException Constructor (com.microsoft.sqlserver.jdbc.IOBuffer, java.lang.String, java.lang.String, int, boolean)
SQLServerException Constructor (com.microsoft.sqlserver.jdbc.IOBuffer, java.lang.String, java.lang.String, com.microsoft.sqlserver.jdbc.StreamError, boolean)
generateStateCode Method (SQLServerException)
makeFromDatabaseError Method (SQLServerException)
makeFromDriverError Method (SQLServerException)
mapFromXopen Method (SQLServerException)
SQLServerParameterMetaData Class