Examples with Comparison org.h2.expression.Comparison used on opensource projects

Example 6 with Comparison

use of org.h2.expression.Comparison in project h2database by h2database.

the class IndexCondition method getSQL.

/**
 * Get the SQL snippet of this comparison.
 *
 * @return the SQL snippet
 */
public String getSQL() {
    if (compareType == Comparison.FALSE) {
        return "FALSE";
    }
    StatementBuilder buff = new StatementBuilder();
    buff.append(column.getSQL());
    switch(compareType) {
        case Comparison.EQUAL:
            buff.append(" = ");
            break;
        case Comparison.EQUAL_NULL_SAFE:
            buff.append(" IS ");
            break;
        case Comparison.BIGGER_EQUAL:
            buff.append(" >= ");
            break;
        case Comparison.BIGGER:
            buff.append(" > ");
            break;
        case Comparison.SMALLER_EQUAL:
            buff.append(" <= ");
            break;
        case Comparison.SMALLER:
            buff.append(" < ");
            break;
        case Comparison.IN_LIST:
            buff.append(" IN(");
            for (Expression e : expressionList) {
                buff.appendExceptFirst(", ");
                buff.append(e.getSQL());
            }
            buff.append(')');
            break;
        case Comparison.IN_QUERY:
            buff.append(" IN(");
            buff.append(expressionQuery.getPlanSQL());
            buff.append(')');
            break;
        case Comparison.SPATIAL_INTERSECTS:
            buff.append(" && ");
            break;
        default:
            DbException.throwInternalError("type=" + compareType);
    }
    if (expression != null) {
        buff.append(expression.getSQL());
    }
    return buff.toString();
}

Example 7 with Comparison

use of org.h2.expression.Comparison in project h2database by h2database.

the class SortOrder method compare.

/**
 * Compare two expression lists.
 *
 * @param a the first expression list
 * @param b the second expression list
 * @return the result of the comparison
 */
@Override
public int compare(Value[] a, Value[] b) {
    for (int i = 0, len = queryColumnIndexes.length; i < len; i++) {
        int idx = queryColumnIndexes[i];
        int type = sortTypes[i];
        Value ao = a[idx];
        Value bo = b[idx];
        boolean aNull = ao == ValueNull.INSTANCE, bNull = bo == ValueNull.INSTANCE;
        if (aNull || bNull) {
            if (aNull == bNull) {
                continue;
            }
            return compareNull(aNull, type);
        }
        int comp = database.compare(ao, bo);
        if (comp != 0) {
            return (type & DESCENDING) == 0 ? comp : -comp;
        }
    }
    return 0;
}

Example 8 with Comparison

use of org.h2.expression.Comparison in project h2database by h2database.

the class CompareLike method optimize.

@Override
public Expression optimize(Session session) {
    left = left.optimize(session);
    right = right.optimize(session);
    if (left.getType() == Value.STRING_IGNORECASE) {
        ignoreCase = true;
    }
    if (left.isValueSet()) {
        Value l = left.getValue(session);
        if (l == ValueNull.INSTANCE) {
            // NULL LIKE something > NULL
            return ValueExpression.getNull();
        }
    }
    if (escape != null) {
        escape = escape.optimize(session);
    }
    if (right.isValueSet() && (escape == null || escape.isValueSet())) {
        if (left.isValueSet()) {
            return ValueExpression.get(getValue(session));
        }
        Value r = right.getValue(session);
        if (r == ValueNull.INSTANCE) {
            // something LIKE NULL > NULL
            return ValueExpression.getNull();
        }
        Value e = escape == null ? null : escape.getValue(session);
        if (e == ValueNull.INSTANCE) {
            return ValueExpression.getNull();
        }
        String p = r.getString();
        initPattern(p, getEscapeChar(e));
        if (invalidPattern) {
            return ValueExpression.getNull();
        }
        if ("%".equals(p)) {
            // optimization for X LIKE '%': convert to X IS NOT NULL
            return new Comparison(session, Comparison.IS_NOT_NULL, left, null).optimize(session);
        }
        if (isFullMatch()) {
            // optimization for X LIKE 'Hello': convert to X = 'Hello'
            Value value = ValueString.get(patternString);
            Expression expr = ValueExpression.get(value);
            return new Comparison(session, Comparison.EQUAL, left, expr).optimize(session);
        }
        isInit = true;
    }
    return this;
}

Example 9 with Comparison

use of org.h2.expression.Comparison in project h2database by h2database.

the class Comparison method getAdditional.

/**
 * Get an additional condition if possible. Example: given two conditions
 * A=B AND B=C, the new condition A=C is returned. Given the two conditions
 * A=1 OR A=2, the new condition A IN(1, 2) is returned.
 *
 * @param session the session
 * @param other the second condition
 * @param and true for AND, false for OR
 * @return null or the third condition
 */
Expression getAdditional(Session session, Comparison other, boolean and) {
    if (compareType == other.compareType && compareType == EQUAL) {
        boolean lc = left.isConstant();
        boolean rc = right.isConstant();
        boolean l2c = other.left.isConstant();
        boolean r2c = other.right.isConstant();
        String l = left.getSQL();
        String l2 = other.left.getSQL();
        String r = right.getSQL();
        String r2 = other.right.getSQL();
        if (and) {
            // must not compare constants. example: NOT(B=2 AND B=3)
            if (!(rc && r2c) && l.equals(l2)) {
                return new Comparison(session, EQUAL, right, other.right);
            } else if (!(rc && l2c) && l.equals(r2)) {
                return new Comparison(session, EQUAL, right, other.left);
            } else if (!(lc && r2c) && r.equals(l2)) {
                return new Comparison(session, EQUAL, left, other.right);
            } else if (!(lc && l2c) && r.equals(r2)) {
                return new Comparison(session, EQUAL, left, other.left);
            }
        } else {
            // a=b OR a=c
            Database db = session.getDatabase();
            if (rc && r2c && l.equals(l2)) {
                return new ConditionIn(db, left, new ArrayList<>(Arrays.asList(right, other.right)));
            } else if (rc && l2c && l.equals(r2)) {
                return new ConditionIn(db, left, new ArrayList<>(Arrays.asList(right, other.left)));
            } else if (lc && r2c && r.equals(l2)) {
                return new ConditionIn(db, right, new ArrayList<>(Arrays.asList(left, other.right)));
            } else if (lc && l2c && r.equals(r2)) {
                return new ConditionIn(db, right, new ArrayList<>(Arrays.asList(left, other.left)));
            }
        }
    }
    return null;
}

Example 10 with Comparison

use of org.h2.expression.Comparison in project h2database by h2database.

the class Table method getBestPlanItem.

/**
 * Get the best plan for the given search mask.
 *
 * @param session the session
 * @param masks per-column comparison bit masks, null means 'always false',
 *              see constants in IndexCondition
 * @param filters all joined table filters
 * @param filter the current table filter index
 * @param sortOrder the sort order
 * @param allColumnsSet the set of all columns
 * @return the plan item
 */
public PlanItem getBestPlanItem(Session session, int[] masks, TableFilter[] filters, int filter, SortOrder sortOrder, HashSet<Column> allColumnsSet) {
    PlanItem item = new PlanItem();
    item.setIndex(getScanIndex(session));
    item.cost = item.getIndex().getCost(session, null, filters, filter, null, allColumnsSet);
    Trace t = session.getTrace();
    if (t.isDebugEnabled()) {
        t.debug("Table      :     potential plan item cost {0} index {1}", item.cost, item.getIndex().getPlanSQL());
    }
    ArrayList<Index> indexes = getIndexes();
    IndexHints indexHints = getIndexHints(filters, filter);
    if (indexes != null && masks != null) {
        for (int i = 1, size = indexes.size(); i < size; i++) {
            Index index = indexes.get(i);
            if (isIndexExcludedByHints(indexHints, index)) {
                continue;
            }
            double cost = index.getCost(session, masks, filters, filter, sortOrder, allColumnsSet);
            if (t.isDebugEnabled()) {
                t.debug("Table      :     potential plan item cost {0} index {1}", cost, index.getPlanSQL());
            }
            if (cost < item.cost) {
                item.cost = cost;
                item.setIndex(index);
            }
        }
    }
    return item;
}