com.feedzai.commons.sql.abstraction.dml.Query Maven / Gradle / Ivy
/*
* Copyright 2014 Feedzai
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.feedzai.commons.sql.abstraction.dml;
import com.google.common.collect.ImmutableList;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import static com.feedzai.commons.sql.abstraction.dml.dialect.SqlBuilder.and;
/**
* Represents a SQL Query.
*
* @author Rui Vilao ([email protected])
* @since 2.0.0
*/
public class Query extends Expression {
/**
* The list of object in the select clause.
*/
private final List selectColumns = new ArrayList<>();
/**
* The list of object in the from clause.
*/
private final List fromColumns = new ArrayList<>();
/**
* The WHERE clause.
*/
private Expression where = null;
/**
* The list of objects in the group by clause.
*/
private final List groupbyColumns = new ArrayList<>();
/**
* The having clause.
*/
private Expression having = null;
/**
* The list of object in the order by clause.
*/
private final List orderbyColumns = new ArrayList<>();
/**
* Limit the number of rows.
*/
private Integer limit = 0;
/**
* Offset before the limit of rows.
*/
private Integer offset = 0;
/**
* Signals the DISTINCT keyword.
*/
private boolean distinct = false;
/**
* Creates a new instance of {@link Query}.
*/
public Query() {
}
@Override
public String translate() {
return translator.translate(this);
}
/**
* Gets the SELECT columns.
*
* @return The SELECT columns.
*/
public List getSelectColumns() {
return ImmutableList.copyOf(selectColumns);
}
/**
* Gets the FROM columns.
*
* @return The FROM columns.
*/
public List getFromColumns() {
return ImmutableList.copyOf(fromColumns);
}
/**
* Gets the WHERE expression.
*
* @return The WHERE expression.
*/
public Expression getWhere() {
return where;
}
/**
* Gets the GROUP BY expressions.
*
* @return The GROUP BY expressions.
*/
public List getGroupbyColumns() {
return ImmutableList.copyOf(groupbyColumns);
}
/**
* Gets the HAVING expression.
*
* @return The HAVING expression.
*/
public Expression getHaving() {
return having;
}
/**
* Gets the ORDER BY expressions.
*
* @return The ORDER BY expressions.
*/
public List getOrderbyColumns() {
return ImmutableList.copyOf(orderbyColumns);
}
/**
* Gets the limit. {@code null} is returned when not applicable.
*
* @return The limit.
*/
public Integer getLimit() {
return limit;
}
/**
* Gets the offset. {@code null} is returned when not applicable.
*
* @return The offset.
*/
public Integer getOffset() {
return offset;
}
/**
* Checks if the SELECT expression is distinct.
*
* @return {@code true} is the SELECT expression is distinct, {@code false} otherwise.
*/
public boolean isDistinct() {
return distinct;
}
/**
* Sets the SELECT expression as DISTINCT.
*
* @return This expression.
*/
public Query distinct() {
this.distinct = true;
return this;
}
/**
* Adds the SELECT columns.
*
* @param selectColumns The columns.
* @return This expression.
*/
public Query select(final Expression... selectColumns) {
if (selectColumns == null) {
return this;
}
return select(Arrays.asList(selectColumns));
}
/**
* Adds the SELECT columns.
*
* @param selectColumns The columns.
* @return This expression.
*/
public Query select(final Collection selectColumns) {
this.selectColumns.addAll(selectColumns);
return this;
}
/**
* Adds the FROM columns.
*
* @param fromColumns The columns.
* @return This expression.
*/
public Query from(final Expression... fromColumns) {
if (fromColumns == null) {
return this;
}
return from(Arrays.asList(fromColumns));
}
/**
* Adds the FROM columns.
*
* @param fromColumns The columns.
* @return This expression.
*/
public Query from(final Collection fromColumns) {
if (fromColumns == null) {
return this;
}
this.fromColumns.addAll(fromColumns);
return this;
}
/**
* The WHERE clause.
*
* If there is no where clause already defined, sets to the defined value.
*
* If there is already an expression for where defined, defines an and expression between old and new clauses.
*
* Example:
*
* query.where(eq(column("col1"),k(1)).andWhere(eq(column("col2"),k(2))
*
* will be translated to
*
* ("col1" = 1) AND ("col2" = 2)
*
*
* @param where The WHERE expression.
* @return This expression.
*/
public Query andWhere(final Expression where) {
if (this.where == null) {
this.where = where;
} else {
this.where = and(this.where.enclose(), where.enclose());
}
return this;
}
/**
* The where clause.
*
* Note:This method replaces any where clauses previously defined.
*
* @param where The object.
* @return This expression.
*/
public Query where(final Expression where) {
this.where = where;
return this;
}
/**
* Adds the GROUP BY columns.
*
* @param groupbyColumns The columns.
* @return This expression.
*/
public Query groupby(final Expression... groupbyColumns) {
if (groupbyColumns == null) {
return this;
}
return groupby(Arrays.asList(groupbyColumns));
}
/**
* Adds the GROUP BY columns.
*
* @param groupbyColumns The columns.
* @return This expression.
*/
public Query groupby(final Collection groupbyColumns) {
if (groupbyColumns == null) {
return this;
}
this.groupbyColumns.addAll(groupbyColumns);
return this;
}
/**
* Adds the HAVING expression.
*
* @param having The having expression.
* @return This expression.
*/
public Query having(final Expression having) {
this.having = having;
return this;
}
/**
* Adds the ORDER BY columns.
*
* @param orderbyColumns The columns.
* @return This expression.
*/
public Query orderby(final Expression... orderbyColumns) {
if (orderbyColumns == null) {
return this;
}
return orderby(Arrays.asList(orderbyColumns));
}
/**
* Adds the ORDER BY columns.
*
* @param orderbyColumns The columns.
* @return This expression.
*/
public Query orderby(final Collection orderbyColumns) {
if (orderbyColumns == null) {
return this;
}
this.orderbyColumns.addAll(orderbyColumns);
return this;
}
/**
* Sets the limit.
*
* @param limit The number of rows that the query returns.
* @return This expression.
*/
public Query limit(final Integer limit) {
this.limit = limit;
return this;
}
/**
* Sets the offset.
*
* @param offset The start position
* @return This expression.
*/
public Query offset(final Integer offset) {
this.offset = offset;
// If we defined offset without limit, force a limit to handle MySQL and others gracefully.
if (limit <= 0) {
limit = Integer.MAX_VALUE - offset;
}
return this;
}
}
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