im.dadoo.cedar.SelectCriteria.java Source code

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Here is the source code for im.dadoo.cedar.SelectCriteria.java

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/*
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package im.dadoo.cedar;

import im.dadoo.cedar.condition.Condition;
import im.dadoo.cedar.order.Order;
import im.dadoo.cedar.util.Util;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.tuple.ImmutablePair;
import org.apache.commons.lang3.tuple.Pair;

/**
 *
 * @author shuwen.zsw
 */
public class SelectCriteria extends TableCriteria {

    private final List<String> fields;
    private final List<Condition> conditions;
    private final List<Order> orders;
    private Pair<String, String> limits;

    public SelectCriteria() {
        super();
        this.fields = new ArrayList<>();
        this.conditions = new ArrayList<>(3);
        this.orders = new ArrayList<>(3);
        this.limits = null;
    }

    public SelectCriteria select() {
        this.fields.add("*");
        return this;
    }

    public SelectCriteria select(String... fields) {
        Collections.addAll(this.fields, fields);
        return this;
    }

    public SelectCriteria select(List<String> fields) {
        this.fields.addAll(fields);
        return this;
    }

    public SelectCriteria from(String table) {
        this.table = table;
        return this;
    }

    public SelectCriteria add(Condition condition) {
        if (condition != null) {
            this.conditions.add(condition);
        }
        return this;
    }

    public SelectCriteria addOrder(Order order) {
        if (order != null) {
            this.orders.add(order);
        }
        return this;
    }

    public SelectCriteria limit(String limit) {
        this.limits = ImmutablePair.of(Util.placeholder(limit), null);
        return this;
    }

    public SelectCriteria limit(String pagecount, String pagesize) {
        this.limits = ImmutablePair.of(Util.placeholder(pagecount), Util.placeholder(pagesize));
        return this;
    }

    @Override
    public String sql() {
        StringBuilder sb = new StringBuilder();
        sb.append("SELECT ");
        //??sql
        if (this.fields == null || this.fields.isEmpty()) {
            return null;
        } else {
            int i = 0;
            for (; i < this.fields.size() - 1; i++) {
                sb.append(this.fields.get(i)).append(", ");
            }
            sb.append(this.fields.get(i)).append(" ");

            //??sql
            if (StringUtils.isBlank(this.table)) {
                return null;
            } else {
                sb.append("FROM ").append(this.table).append(" ");

                //?
                if (this.conditions != null && !this.conditions.isEmpty()) {
                    sb.append("WHERE ").append(this.makeConditionSql(this.conditions.get(0))).append(" ");
                    if (this.conditions.size() > 1) {
                        for (i = 1; i < this.conditions.size(); i++) {
                            sb.append("AND ").append(this.makeConditionSql(this.conditions.get(i))).append(" ");
                        }
                    }
                }

                //??
                if (this.orders != null && !this.orders.isEmpty()) {
                    sb.append("ORDER BY ").append(this.makeOrderSql(this.orders.get(0))).append(" ");
                    if (this.orders.size() > 1) {
                        for (i = 1; i < this.orders.size(); i++) {
                            sb.append(", ").append(this.makeOrderSql(this.orders.get(i))).append(" ");
                        }
                    }
                }
                //limit?
                if (this.limits != null) {
                    if (this.limits.getRight() == null) {
                        sb.append("LIMIT ").append(this.limits.getLeft());
                    } else {
                        sb.append("LIMIT ").append(this.limits.getLeft()).append(", ")
                                .append(this.limits.getRight());
                    }
                }
            }
        }
        return sb.toString();
    }

    private String makeOrderSql(Order order) {
        StringBuilder sb = new StringBuilder();
        if (order != null && order.getField() != null && order.getMode() != null) {
            sb.append(order.getField()).append(" ").append(order.getMode().getWord());
        }
        return sb.toString();
    }

    private String makeConditionSql(Condition condition) {
        StringBuilder sb = new StringBuilder();
        if (condition != null && condition.getField() != null && condition.getOp() != null
                && condition.getValue() != null) {
            switch (condition.getOp()) {
            case EQ:
            case GT:
            case LT:
                sb.append(condition.getField()).append(" ").append(condition.getOp().getWord()).append(" ")
                        .append(condition.getValue());
                break;
            case IN:
                String temp = null;
                //??
                if (condition.getValue() instanceof String) {
                    temp = (String) condition.getValue();
                } else if (condition.getValue() instanceof SelectCriteria) {
                    temp = ((SelectCriteria) condition.getValue()).sql();
                }
                sb.append(condition.getField()).append(" ").append(condition.getOp().getWord()).append(" ")
                        .append("( ").append(temp).append(" )");
                break;
            case BETWEEN:
                Pair<String, String> pair = (Pair<String, String>) condition.getValue();
                sb.append(condition.getField()).append(" ").append(condition.getOp().getWord()).append(" ")
                        .append(pair.getLeft()).append(" ").append("AND").append(" ").append(pair.getRight());
                break;
            }
        }
        return sb.toString();
    }
}