package com.avaje.ebean;
import com.avaje.ebean.RawSql.ColumnMapping;
import com.avaje.ebean.RawSql.Sql;
/**
* Builds RawSql instances from a SQL string and column mappings.
* <p>
* Note that RawSql can also be defined in ebean-orm.xml files and be used as a
* named query.
* </p>
*
* @author rbygrave
*
* @see RawSql
*/
public class RawSqlBuilder {
/**
* Special property name assigned to a DB column that should be ignored.
*/
public static final String IGNORE_COLUMN = "$$_IGNORE_COLUMN_$$";
private final Sql sql;
private final ColumnMapping columnMapping;
/**
* Return an unparsed RawSqlBuilder. Unlike a parsed one this query can not be
* modified - so no additional WHERE or HAVING expressions can be added to
* this query.
*/
public static RawSqlBuilder unparsed(String sql) {
Sql s = new Sql(sql);
return new RawSqlBuilder(s, new ColumnMapping());
}
/**
* Return a RawSqlBuilder parsing the sql.
* <p>
* The sql statement will be parsed so that Ebean can determine where it can
* insert additional WHERE or HAVING expressions.
* </p>
* <p>
* Additionally the selected columns are parsed to determine the column
* ordering. This also means additional checks can be made with the column
* mapping - specifically we can check that all columns are mapped and that
* correct column names are entered into the mapping.
* </p>
*/
public static RawSqlBuilder parse(String sql) {
Sql sql2 = DRawSqlParser.parse(sql);
String select = sql2.getPreFrom();
ColumnMapping mapping = DRawSqlColumnsParser.parse(select);
return new RawSqlBuilder(sql2, mapping);
}
private RawSqlBuilder(Sql sql, ColumnMapping columnMapping) {
this.sql = sql;
this.columnMapping = columnMapping;
}
/**
* Set the mapping of a DB Column to a bean property.
* <p>
* For Unparsed SQL the columnMapping MUST be defined in the same order that
* the columns appear in the SQL statement.
* </p>
*
* @param dbColumn
* the DB column that we are mapping to a bean property
* @param propertyName
* the bean property that we are mapping the DB column to.
*/
public RawSqlBuilder columnMapping(String dbColumn, String propertyName) {
columnMapping.columnMapping(dbColumn, propertyName);
return this;
}
/**
* Ignore this DB column. It is not mapped to any bean property.
*/
public RawSqlBuilder columnMappingIgnore(String dbColumn) {
return columnMapping(dbColumn, IGNORE_COLUMN);
}
/**
* Create the immutable RawSql object. Do this after all the column mapping
* has been defined.
*/
public RawSql create() {
return new RawSql(sql, columnMapping.createImmutableCopy());
}
/**
* Return the internal parsed Sql object (for testing).
*/
protected Sql getSql() {
return sql;
}
}