前几天做一个小系统,数据库选了SQLite,从网上下载了一个SQLite与Hibernate整合的方言类配进系统
import java.sql.Types;
import org.hibernate.Hibernate;
import org.hibernate.dialect.Dialect;
import org.hibernate.dialect.function.SQLFunctionTemplate;
import org.hibernate.dialect.function.StandardSQLFunction;
import org.hibernate.dialect.function.VarArgsSQLFunction;
public class SQLiteDialect extends Dialect {
public SQLiteDialect() {
super();
registerColumnType(Types.BIT, "integer");
registerColumnType(Types.TINYINT, "tinyint");
registerColumnType(Types.SMALLINT, "smallint");
registerColumnType(Types.INTEGER, "integer");
registerColumnType(Types.BIGINT, "bigint");
registerColumnType(Types.FLOAT, "float");
registerColumnType(Types.REAL, "real");
registerColumnType(Types.DOUBLE, "double");
registerColumnType(Types.NUMERIC, "numeric");
registerColumnType(Types.DECIMAL, "decimal");
registerColumnType(Types.CHAR, "char");
registerColumnType(Types.VARCHAR, "varchar");
registerColumnType(Types.LONGVARCHAR, "longvarchar");
registerColumnType(Types.DATE, "date");
registerColumnType(Types.TIME, "time");
registerColumnType(Types.TIMESTAMP, "timestamp");
registerColumnType(Types.BINARY, "blob");
registerColumnType(Types.VARBINARY, "blob");
registerColumnType(Types.LONGVARBINARY, "blob");
registerColumnType(Types.BLOB, "blob");
registerColumnType(Types.CLOB, "clob");
registerColumnType(Types.BOOLEAN, "integer");
registerFunction("concat", new VarArgsSQLFunction(Hibernate.STRING, "",
"||", ""));
registerFunction("mod", new SQLFunctionTemplate(Hibernate.INTEGER,
"?1 % ?2"));
registerFunction("substr", new StandardSQLFunction("substr",
Hibernate.STRING));
registerFunction("substring", new StandardSQLFunction("substr",
Hibernate.STRING));
}
public boolean supportsIdentityColumns() {
return true;
}
public boolean hasDataTypeInIdentityColumn() {
return false;
}
public String getIdentityColumnString() {
return "integer";
}
public String getIdentitySelectString() {
return "select last_insert_rowid()";
}
public boolean supportsLimit() {
return true;
}
protected String getLimitString(String query, boolean hasOffset) {
return new StringBuffer(query.length() + 20).append(query).append(
hasOffset ? " limit ? offset ?" : " limit ?").toString();
}
public boolean supportsTemporaryTables() {
return true;
}
public String getCreateTemporaryTableString() {
return "create temporary table if not exists";
}
public boolean dropTemporaryTableAfterUse() {
return false;
}
public boolean supportsCurrentTimestampSelection() {
return true;
}
public boolean isCurrentTimestampSelectStringCallable() {
return false;
}
public String getCurrentTimestampSelectString() {
return "select current_timestamp";
}
public boolean supportsUnionAll() {
return true;
}
public boolean hasAlterTable() {
return false;
}
public boolean dropConstraints() {
return false;
}
public String getAddColumnString() {
return "add column";
}
public String getForUpdateString() {
return "";
}
public boolean supportsOuterJoinForUpdate() {
return false;
}
public String getDropForeignKeyString() {
throw new UnsupportedOperationException(
"No drop foreign key syntax supported by SQLiteDialect");
}
public String getAddForeignKeyConstraintString(String constraintName,
String[] foreignKey, String referencedTable, String[] primaryKey,
boolean referencesPrimaryKey) {
throw new UnsupportedOperationException(
"No add foreign key syntax supported by SQLiteDialect");
}
public String getAddPrimaryKeyConstraintString(String constraintName) {
throw new UnsupportedOperationException(
"No add primary key syntax supported by SQLiteDialect");
}
public boolean supportsIfExistsBeforeTableName() {
return true;
}
public boolean supportsCascadeDelete() {
return false;
}
}
但是在使用中抛了一个异常
org.hibernate.MappingException: No Dialect mapping for JDBC type: 0
到java.sql.Types类里看了一下这个0的类型是指null
public final static int NULL = 0;
解决方法:
在这个类的构造方法里加一句
registerHibernateType(Types.NULL, "null");