com.avaje.ebean.config.dbplatform.DatabasePlatform Maven / Gradle / Ivy
package com.avaje.ebean.config.dbplatform;
import com.avaje.ebean.BackgroundExecutor;
import com.avaje.ebean.Query;
import com.avaje.ebean.config.CustomDbTypeMapping;
import com.avaje.ebean.config.DbTypeConfig;
import com.avaje.ebean.config.PersistBatch;
import com.avaje.ebean.config.Platform;
import com.avaje.ebean.config.ServerConfig;
import com.avaje.ebean.dbmigration.ddlgeneration.DdlHandler;
import com.avaje.ebean.dbmigration.ddlgeneration.platform.PlatformDdl;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;
/**
* Database platform specific settings.
*/
public class DatabasePlatform {
private static final Logger logger = LoggerFactory.getLogger(DatabasePlatform.class);
/**
* Behavior used when ending a query only transaction (at read committed isolation level).
*/
public enum OnQueryOnly {
/**
* Rollback the transaction.
*/
ROLLBACK,
/**
* Commit the transaction
*/
COMMIT
}
/**
* Set to true for MySql, no other jdbc drivers need this workaround.
*/
protected boolean useExtraTransactionOnIterateSecondaryQueries;
/**
* The behaviour used when ending a read only transaction at read committed isolation level.
*/
protected OnQueryOnly onQueryOnly = OnQueryOnly.ROLLBACK;
/**
* The open quote used by quoted identifiers.
*/
protected String openQuote = "\"";
/**
* The close quote used by quoted identifiers.
*/
protected String closeQuote = "\"";
/**
* For limit/offset, row_number etc limiting of SQL queries.
*/
protected SqlLimiter sqlLimiter = new LimitOffsetSqlLimiter();
/**
* Limit/offset support for SqlQuery only.
*/
protected BasicSqlLimiter basicSqlLimiter = new BasicSqlLimitOffset();
/**
* Mapping of JDBC to Database types.
*/
protected DbPlatformTypeMapping dbTypeMap = new DbPlatformTypeMapping();
/**
* Default values for DB columns.
*/
protected DbDefaultValue dbDefaultValue = new DbDefaultValue();
/**
* Set to true if the DB has native UUID type support.
*/
protected boolean nativeUuidType;
/**
* Defines DB identity/sequence features.
*/
protected DbIdentity dbIdentity = new DbIdentity();
/**
* The history support for this database platform.
*/
protected DbHistorySupport historySupport;
/**
* The JDBC type to map booleans to (by default).
*/
protected int booleanDbType = Types.BOOLEAN;
/**
* The JDBC type to map Blob to.
*/
protected int blobDbType = Types.BLOB;
/**
* The JDBC type to map Clob to.
*/
protected int clobDbType = Types.CLOB;
/**
* For Oracle treat empty strings as null.
*/
protected boolean treatEmptyStringsAsNull;
/**
* The database platform name.
*/
protected String name = "generic";
protected String columnAliasPrefix = "c";
protected String tableAliasPlaceHolder = "${ta}";
/**
* Use a BackTick ` at the beginning and end of table or column names that you
* want to use quoted identifiers for. The backticks get converted to the
* appropriate characters in convertQuotedIdentifiers
*/
private static final char BACK_TICK = '`';
/**
* The like clause. Can be overridden to disable default escape character.
*/
protected String likeClause = "like ?";
protected DbEncrypt dbEncrypt;
protected boolean idInExpandedForm;
protected boolean selectCountWithAlias;
/**
* If set then use the FORWARD ONLY hint when creating ResultSets for
* findIterate() and findVisit().
*/
protected boolean forwardOnlyHintOnFindIterate;
/**
* By default we use JDBC batch when cascading (except for SQL Server).
*/
protected PersistBatch persistBatchOnCascade = PersistBatch.ALL;
protected PlatformDdl platformDdl;
/**
* The maximum length of table names - used specifically when derived
* default table names for intersection tables.
*/
protected int maxTableNameLength = 60;
/**
* A value of 60 is a reasonable default for all databases except
* Oracle (limited to 30) and DB2 (limited to 18).
*/
protected int maxConstraintNameLength = 60;
protected boolean supportsNativeIlike;
/**
* Instantiates a new database platform.
*/
public DatabasePlatform() {
}
/**
* Configure UUID Storage etc based on ServerConfig settings.
*/
public void configure(DbTypeConfig config) {
addGeoTypes(config.getGeometrySRID());
configureIdType(config.getIdType());
dbTypeMap.config(nativeUuidType, config.getDbUuid());
for (CustomDbTypeMapping mapping : config.getCustomTypeMappings()) {
if (platformMatch(mapping.getPlatform())) {
dbTypeMap.put(mapping.getType(), parse(mapping.getColumnDefinition()));
}
}
}
protected void configureIdType(IdType idType) {
if (idType != null) {
this.dbIdentity.setIdType(idType);
}
}
protected void addGeoTypes(int srid) {
// default has no geo type support
}
private DbPlatformType parse(String columnDefinition) {
return DbPlatformType.parse(columnDefinition);
}
private boolean platformMatch(Platform platform) {
return platform == null || platform.name().equalsIgnoreCase(name);
}
/**
* Return true if this matches the given platform.
*/
public boolean isPlatform(Platform platform) {
return platform.name().equalsIgnoreCase(name);
}
/**
* Return the name of the DatabasePlatform.
*
* "generic" is returned when no specific database platform has been set or
* found.
*
*/
public String getName() {
return name;
}
/**
* Return true if this database platform supports native ILIKE expression.
*/
public boolean isSupportsNativeIlike() {
return supportsNativeIlike;
}
/**
* Return the maximum table name length.
*
* This is used when deriving names of intersection tables.
*
*/
public int getMaxTableNameLength() {
return maxTableNameLength;
}
/**
* Return the maximum constraint name allowed for the platform.
*/
public int getMaxConstraintNameLength() {
return maxConstraintNameLength;
}
/**
* Return the platform specific DDL.
*/
public PlatformDdl getPlatformDdl() {
return platformDdl;
}
/**
* Create and return a DDL handler for generating DDL scripts.
*/
public DdlHandler createDdlHandler(ServerConfig serverConfig) {
return platformDdl.createDdlHandler(serverConfig);
}
/**
* Return true if the JDBC driver does not allow additional queries to execute
* when a resultSet is being 'streamed' as is the case with findEach() etc.
*
* Honestly, this is a workaround for a stupid MySql JDBC driver limitation.
*
*/
public boolean useExtraTransactionOnIterateSecondaryQueries() {
return useExtraTransactionOnIterateSecondaryQueries;
}
/**
* Return a DB Sequence based IdGenerator.
*
* @param be the BackgroundExecutor that can be used to load the sequence if
* desired
* @param ds the DataSource
* @param seqName the name of the sequence
* @param batchSize the number of sequences that should be loaded
*/
public PlatformIdGenerator createSequenceIdGenerator(BackgroundExecutor be, DataSource ds, String seqName, int batchSize) {
return null;
}
/**
* Return the behaviour to use when ending a read only transaction.
*/
public OnQueryOnly getOnQueryOnly() {
return onQueryOnly;
}
/**
* Set the behaviour to use when ending a read only transaction.
*/
public void setOnQueryOnly(OnQueryOnly onQueryOnly) {
this.onQueryOnly = onQueryOnly;
}
/**
* Return the DbEncrypt handler for this DB platform.
*/
public DbEncrypt getDbEncrypt() {
return dbEncrypt;
}
/**
* Set the DbEncrypt handler for this DB platform.
*/
public void setDbEncrypt(DbEncrypt dbEncrypt) {
this.dbEncrypt = dbEncrypt;
}
/**
* Return the history support for this database platform.
*/
public DbHistorySupport getHistorySupport() {
return historySupport;
}
/**
* Set the history support for this database platform.
*/
public void setHistorySupport(DbHistorySupport historySupport) {
this.historySupport = historySupport;
}
/**
* Return true if the DB supports native UUID.
*/
public boolean isNativeUuidType() {
return nativeUuidType;
}
/**
* Return the mapping of JDBC to DB types.
*
* @return the db type map
*/
public DbPlatformTypeMapping getDbTypeMap() {
return dbTypeMap;
}
/**
* Return the mapping for DB column default values.
*/
public DbDefaultValue getDbDefaultValue() {
return dbDefaultValue;
}
/**
* Return the column alias prefix.
*/
public String getColumnAliasPrefix() {
return columnAliasPrefix;
}
/**
* Set the column alias prefix.
*/
public void setColumnAliasPrefix(String columnAliasPrefix) {
this.columnAliasPrefix = columnAliasPrefix;
}
/**
* Return the table alias placeholder.
*/
public String getTableAliasPlaceHolder() {
return tableAliasPlaceHolder;
}
/**
* Set the table alias placeholder.
*/
public void setTableAliasPlaceHolder(String tableAliasPlaceHolder) {
this.tableAliasPlaceHolder = tableAliasPlaceHolder;
}
/**
* Return the close quote for quoted identifiers.
*
* @return the close quote
*/
public String getCloseQuote() {
return closeQuote;
}
/**
* Return the open quote for quoted identifiers.
*
* @return the open quote
*/
public String getOpenQuote() {
return openQuote;
}
/**
* Return the JDBC type used to store booleans.
*
* @return the boolean db type
*/
public int getBooleanDbType() {
return booleanDbType;
}
/**
* Return the data type that should be used for Blob.
*
* This is typically Types.BLOB but for Postgres is Types.LONGVARBINARY for
* example.
*
*/
public int getBlobDbType() {
return blobDbType;
}
/**
* Return the data type that should be used for Clob.
*
* This is typically Types.CLOB but for Postgres is Types.VARCHAR.
*
*/
public int getClobDbType() {
return clobDbType;
}
/**
* Return true if empty strings should be treated as null.
*
* @return true, if checks if is treat empty strings as null
*/
public boolean isTreatEmptyStringsAsNull() {
return treatEmptyStringsAsNull;
}
/**
* Return true if a compound ID in (...) type expression needs to be in
* expanded form of (a=? and b=?) or (a=? and b=?) or ... rather than (a,b) in
* ((?,?),(?,?),...);
*/
public boolean isIdInExpandedForm() {
return idInExpandedForm;
}
/**
* Return true if the ResultSet TYPE_FORWARD_ONLY Hint should be used on
* findIterate() and findVisit() PreparedStatements.
*
* This specifically is required for MySql when processing large results.
*
*/
public boolean isForwardOnlyHintOnFindIterate() {
return forwardOnlyHintOnFindIterate;
}
/**
* Set to true if the ResultSet TYPE_FORWARD_ONLY Hint should be used by default on findIterate PreparedStatements.
*/
public void setForwardOnlyHintOnFindIterate(boolean forwardOnlyHintOnFindIterate) {
this.forwardOnlyHintOnFindIterate = forwardOnlyHintOnFindIterate;
}
/**
* Return the DB identity/sequence features for this platform.
*
* @return the db identity
*/
public DbIdentity getDbIdentity() {
return dbIdentity;
}
/**
* Return the SqlLimiter used to apply additional sql around a query to limit
* its results.
*
* Basically add the clauses for limit/offset, rownum, row_number().
*
*
* @return the sql limiter
*/
public SqlLimiter getSqlLimiter() {
return sqlLimiter;
}
/**
* Return the BasicSqlLimiter for limit/offset of SqlQuery queries.
*/
public BasicSqlLimiter getBasicSqlLimiter() {
return basicSqlLimiter;
}
/**
* Set the DB TRUE literal (from the registered boolean ScalarType)
*/
public void setDbTrueLiteral(String dbTrueLiteral) {
this.dbDefaultValue.setTrue(dbTrueLiteral);
}
/**
* Set the DB FALSE literal (from the registered boolean ScalarType)
*/
public void setDbFalseLiteral(String dbFalseLiteral) {
this.dbDefaultValue.setFalse(dbFalseLiteral);
}
/**
* Convert backticks to the platform specific open quote and close quote
*
* Specific plugins may implement this method to cater for platform specific
* naming rules.
*
*
* @param dbName the db name
* @return the string
*/
public String convertQuotedIdentifiers(String dbName) {
// Ignore null values e.g. schema name or catalog
if (dbName != null && !dbName.isEmpty()) {
if (dbName.charAt(0) == BACK_TICK) {
if (dbName.charAt(dbName.length() - 1) == BACK_TICK) {
String quotedName = getOpenQuote();
quotedName += dbName.substring(1, dbName.length() - 1);
quotedName += getCloseQuote();
return quotedName;
} else {
logger.error("Missing backquote on [" + dbName + "]");
}
}
}
return dbName;
}
/**
* Set to true if select count against anonymous view requires an alias.
*/
public boolean isSelectCountWithAlias() {
return selectCountWithAlias;
}
public String completeSql(String sql, Query query) {
if (Boolean.TRUE.equals(query.isForUpdate())) {
sql = withForUpdate(sql);
}
return sql;
}
protected String withForUpdate(String sql) {
// silently assume the database does not support the "for update" clause.
logger.info("it seems your database does not support the 'for update' clause");
return sql;
}
/**
* Returns the like clause used by this database platform.
*
* This may include an escape clause to disable a default escape character.
*/
public String getLikeClause() {
return likeClause;
}
/**
* Return the platform default JDBC batch mode for persist cascade.
*/
public PersistBatch getPersistBatchOnCascade() {
return persistBatchOnCascade;
}
/**
* Return true if the table exists.
*/
public boolean tableExists(Connection connection, String catalog, String schema, String table) throws SQLException {
DatabaseMetaData metaData = connection.getMetaData();
ResultSet tables = metaData.getTables(catalog, schema, table, null);
try {
return tables.next();
} finally {
close(tables);
}
}
/**
* Close the resultSet.
*/
protected void close(ResultSet resultSet) {
try {
resultSet.close();
} catch (SQLException e) {
logger.error("Error closing resultSet", e);
}
}
}
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