root / trunk / libraries / libGDBMS / src / com / hardcode / gdbms / engine / instruction / SelectAdapter.java @ 466
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/* Generated by Together */
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package com.hardcode.gdbms.engine.instruction; |
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import com.hardcode.gdbms.engine.data.DataSource; |
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/**
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* Adapta el nodo que representa una instrucci?n select en el ?rbol sint?ctico
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* de entrada
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*
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* @author Fernando Gonz?lez Cort?s
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*/
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public class SelectAdapter extends Adapter { |
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private DataSource[] tables; |
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private DataSource dataSource; |
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/**
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* Obtiene las tablas de la cl?usula FROM de la instrucci?n
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*
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* @return Tablas de la select
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*
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* @throws SemanticException Si se produce un error sem?ntico
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*/
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public DataSource[] getTables() throws SemanticException { |
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return ((TableListAdapter) getChilds()[1]).getTables(); |
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} |
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/**
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* Obtiene las expresiones de los campos de la cl?usula SELECT o null si
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* hay un ''.
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*
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* @return Expresiones de los campos
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*/
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public Expression[] getFieldsExpression() { |
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return ((SelectColsAdapter) getChilds()[0]).getFieldsExpression(); |
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} |
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/**
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* Obtiene el alias de los campos. Al igual que getFieldsExpression,
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* devuelve null si se selecciona ''
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*
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* @return Array de strings con los alias
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*/
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public String[] getFieldsAlias() { |
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return ((SelectColsAdapter) getChilds()[0]).getFieldsAlias(); |
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} |
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/**
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* Devuelve true si la palabra clave DISTINCT se us? y false en caso
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* contrario
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*
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* @return Devuelve true si se utiliz? la palabra clave DISTINCT
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*/
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public boolean isDistinct() { |
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return ((SelectColsAdapter) getChilds()[0]).isDistinct(); |
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} |
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/**
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* @see com.hardcode.gdbms.engine.instruction.SelectInstruction#setTables(com.hardcode.gdbms.engine.data.DataSource[])
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*/
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public void setTables(DataSource[] tables) { |
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this.tables = tables;
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} |
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/**
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* Obtiene el origen de datos para los campos a la hora de evaluar las
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* expresiones
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*
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* @return
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*/
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public DataSource getDataSource() { |
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return dataSource;
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} |
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/**
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* Establece el origen de datos para los campos a la hora de evaluar las
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* expresiones
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*
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* @param source
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*/
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public void setDataSource(DataSource source) { |
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dataSource = source; |
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} |
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/**
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* @see com.hardcode.gdbms.engine.instruction.SelectInstruction#getWhereExpression()
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*/
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public Expression getWhereExpression() throws SemanticException { |
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Adapter[] hijos = getChilds();
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if (hijos.length < 3) { |
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return null; |
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} |
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if (hijos[2] instanceof WhereAdapter) { |
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return ((WhereAdapter) hijos[2]).getExpression(); |
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} else {
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return null; |
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} |
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} |
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} |