Saturday, June 19, 2010

Remove Non Printable Characters with sed

Took a while to find this and the exact syntax but here its, removing all non ascii chars.
$ sed 's/[^ -~]//g' < B2.java > BeanUtils.java 

Thursday, June 17, 2010

SQLite Primary Keys and Hibernate

 SQLite is a modern, compact and stable database. Using Hibernate on top of SQLite proved to be a challenge with Primary Keys.

Here the reason why the autoincrement does not work... even if we would specify it the table creation would mess you up with two primary key definitions. See the next pictures why and how...






So you need the following SQLiteDialect that is being found accross the web... here a copy.


/**
 * 
 */
package org.territory;

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;

/**
 * @author 751818
 * 
 */
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.NULL, "null");
  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 supportsInsertSelectIdentity() { return true; // As
  * specify in NHibernate dialect }
  */

 public boolean hasDataTypeInIdentityColumn() {
  return false; // As specify in NHibernate dialect
 }

 /*
  * public String appendIdentitySelectToInsert(String insertString) { return
  * new StringBuffer(insertString.length()+30). // As specify in NHibernate
  * dialect append(insertString).
  * append("; ").append(getIdentitySelectString()). toString(); }
  */

 public String getIdentityColumnString() {
  return "INTEGER";
  // return "integer";
 }

 public String getIdentitySelectString() {
  return "select last_insert_rowid()";
 }

 public boolean supportsLimit() {
  return true;
 }

 public 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; // As specify in NHibernate dialect
 }

 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;
 }

 /*
  * (non-Javadoc)
  * 
  * @see org.hibernate.dialect.Dialect#getNativeIdentifierGeneratorClass()
  */
 @Override
 public Class getNativeIdentifierGeneratorClass() {
  // TODO Auto-generated method stub
  return super.getNativeIdentifierGeneratorClass();
 }
}

Next set the dialect of the Hibernate mapping...
Next set the sequence generate for the ID's that you want AUTOINCREMENT'ed.

And that should give you an incremented value of your id....