ei.ne.ke.cassandra.cql3.template.DeleteStatementBuilder.java Source code

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Here is the source code for ei.ne.ke.cassandra.cql3.template.DeleteStatementBuilder.java

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/*
 * Copyright 2013 EK3 Technologies, Inc.
 *
 * 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 ei.ne.ke.cassandra.cql3.template;

import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;

import org.apache.commons.lang.StringUtils;

import com.google.common.base.Functions;
import com.google.common.base.Preconditions;
import com.google.common.collect.Collections2;
import com.google.common.collect.Lists;

/**
 * Builder for CQL3 DELETE statements.
 */
public class DeleteStatementBuilder implements Mutating {

    private Collection<String> selection;
    private Identifier table;
    private Collection<Option> options;
    private Collection<Relation> relations;
    private boolean usingTimestamp;

    /**
     *
     */
    DeleteStatementBuilder() {
        this.selection = Lists.newArrayList();
        this.table = null;
        this.options = Lists.newArrayList();
        this.relations = Lists.newArrayList();
        this.usingTimestamp = false;
    }

    /**
     *
     *
     * @param columns
     * @return this builder.
     */
    public DeleteStatementBuilder columns(String... columns) {
        this.selection.addAll(Arrays.asList(columns));
        return this;
    }

    /**
     *
     *
     * @param selection
     */
    public DeleteStatementBuilder values(Collection<String> values) {
        this.selection.addAll(values);
        return this;
    }

    /**
     *
     *
     * @param identifier
     * @return this builder.
     */
    public DeleteStatementBuilder from(String identifier) {
        this.table = new Identifier(identifier);
        return this;
    }

    /**
     *
     *
     * @param timestamp
     * @return this builder.
     */
    public DeleteStatementBuilder usingTimestamp(long value) {
        this.options.add(Option.timestamp(value));
        usingTimestamp = true;
        return this;
    }

    /**
     *
     *
     * @param identifier
     * @param numVariables
     * @return
     */
    public DeleteStatementBuilder where(String identifier, int numVariables) {
        relations.add(new In(new Identifier(identifier), Collections.nCopies(numVariables, Term.VARIABLE)));
        return this;
    }

    /**
     *
     *
     * @param identifier
     * @param comparator
     * @return this builder.
     */
    public DeleteStatementBuilder where(String identifier, String comparator) {
        relations.add(new Relation(new Identifier(identifier), Comparator.getEnum(comparator)));
        return this;
    }

    /**
     * Adds a relation for each of the given column name with the given
     * comparator and a variable value.
     *
     * @param relations
     * @param comparator
     * @return this builder.
     */
    public DeleteStatementBuilder where(Collection<String> values, String comparator) {
        if (values != null) {
            for (String value : values) {
                relations.add(new Relation(new Identifier(value), Comparator.getEnum(comparator)));
            }
        }
        return this;
    }

    /**
     * Adds a relation for the given identifier, comparator, and literal value.
     * @param identifier the identifier.
     * @param comparator the comparator.
     * @param value the literal value.
     * @return this builder.
     */
    public DeleteStatementBuilder where(String identifier, String comparator, String value) {
        relations.add(new Relation(new Identifier(identifier), Comparator.getEnum(comparator), new Term(value)));
        return this;
    }

    /**
     * Adds a relation for the given identifier and values for an IN clause.
     * @param identifier the identifier.
     * @param in the values used in the IN clause
     * @return this builder.
     */
    public DeleteStatementBuilder where(String identifier, Collection<String> ins) {
        Collection<Term> terms = Lists.newArrayListWithExpectedSize(ins.size());
        for (String in : ins) {
            terms.add(new Term(in));
        }
        relations.add(new In(new Identifier(identifier), terms));
        return this;
    }

    /**
     * Adds a relation.
     * @param relation the relation.
     * @return this builder.
     */
    public DeleteStatementBuilder where(Relation relation) {
        relations.add(relation);
        return this;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String build() {
        Preconditions.checkNotNull(table, "You must set the name of a table");
        StringBuilder sb = new StringBuilder();
        sb.append("DELETE ");
        sb.append(StringUtils.join(selection, ", "));
        sb.append(" FROM ");
        sb.append(table);
        if (!options.isEmpty()) {
            sb.append(" USING ");
            sb.append(StringUtils.join(Collections2.transform(options, Functions.toStringFunction()), " AND "));
        }
        if (!relations.isEmpty()) {
            sb.append(" WHERE ");
            sb.append(StringUtils.join(Collections2.transform(relations, Functions.toStringFunction()), " AND "));
        }
        sb.append(";");
        return sb.toString();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean usingTimestamp() {
        return usingTimestamp;
    }

}