SQLite数据库 hibernate配置方言

配置hibernate时，设置数据的方言是很重要的，SQLite是一款内存式小数据库，在项目中很有用，数据查询和更新速度不错。但是，hibernate没有针对SQLite的方言。这就需要我们自己配置了。下面是SQLite数据库的方言类。

package xidian.sms.common;
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;
 }
}