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

Example 21 with ExpressionColumn

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

the class Query method initOrder.

/**
 * Initialize the order by list. This call may extend the expressions list.
 *
 * @param session the session
 * @param expressions the select list expressions
 * @param expressionSQL the select list SQL snippets
 * @param orderList the order by list
 * @param visible the number of visible columns in the select list
 * @param mustBeInResult all order by expressions must be in the select list
 * @param filters the table filters
 */
static void initOrder(Session session, ArrayList<Expression> expressions, ArrayList<String> expressionSQL, ArrayList<SelectOrderBy> orderList, int visible, boolean mustBeInResult, ArrayList<TableFilter> filters) {
    Database db = session.getDatabase();
    for (SelectOrderBy o : orderList) {
        Expression e = o.expression;
        if (e == null) {
            continue;
        }
        // special case: SELECT 1 AS A FROM DUAL ORDER BY A
        // (oracle supports it, but only in order by, not in group by and
        // not in having):
        // SELECT 1 AS A FROM DUAL ORDER BY -A
        boolean isAlias = false;
        int idx = expressions.size();
        if (e instanceof ExpressionColumn) {
            // order by expression
            ExpressionColumn exprCol = (ExpressionColumn) e;
            String tableAlias = exprCol.getOriginalTableAliasName();
            String col = exprCol.getOriginalColumnName();
            for (int j = 0; j < visible; j++) {
                boolean found = false;
                Expression ec = expressions.get(j);
                if (ec instanceof ExpressionColumn) {
                    // select expression
                    ExpressionColumn c = (ExpressionColumn) ec;
                    found = db.equalsIdentifiers(col, c.getColumnName());
                    if (found && tableAlias != null) {
                        String ca = c.getOriginalTableAliasName();
                        if (ca == null) {
                            found = false;
                            if (filters != null) {
                                // select id from test order by test.id
                                for (TableFilter f : filters) {
                                    if (db.equalsIdentifiers(f.getTableAlias(), tableAlias)) {
                                        found = true;
                                        break;
                                    }
                                }
                            }
                        } else {
                            found = db.equalsIdentifiers(ca, tableAlias);
                        }
                    }
                } else if (!(ec instanceof Alias)) {
                    continue;
                } else if (tableAlias == null && db.equalsIdentifiers(col, ec.getAlias())) {
                    found = true;
                } else {
                    Expression ec2 = ec.getNonAliasExpression();
                    if (ec2 instanceof ExpressionColumn) {
                        ExpressionColumn c2 = (ExpressionColumn) ec2;
                        String ta = exprCol.getSQL();
                        String tb = c2.getSQL();
                        String s2 = c2.getColumnName();
                        found = db.equalsIdentifiers(col, s2);
                        if (!db.equalsIdentifiers(ta, tb)) {
                            found = false;
                        }
                    }
                }
                if (found) {
                    idx = j;
                    isAlias = true;
                    break;
                }
            }
        } else {
            String s = e.getSQL();
            if (expressionSQL != null) {
                for (int j = 0, size = expressionSQL.size(); j < size; j++) {
                    String s2 = expressionSQL.get(j);
                    if (db.equalsIdentifiers(s2, s)) {
                        idx = j;
                        isAlias = true;
                        break;
                    }
                }
            }
        }
        if (!isAlias) {
            if (mustBeInResult) {
                throw DbException.get(ErrorCode.ORDER_BY_NOT_IN_RESULT, e.getSQL());
            }
            expressions.add(e);
            String sql = e.getSQL();
            expressionSQL.add(sql);
        }
        o.columnIndexExpr = ValueExpression.get(ValueInt.get(idx + 1));
        o.expression = expressions.get(idx).getNonAliasExpression();
    }
}

Example 22 with ExpressionColumn

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

the class SelectUnion method prepare.

@Override
public void prepare() {
    if (isPrepared) {
        // sometimes a subquery is prepared twice (CREATE TABLE AS SELECT)
        return;
    }
    if (SysProperties.CHECK && !checkInit) {
        DbException.throwInternalError("not initialized");
    }
    isPrepared = true;
    left.prepare();
    right.prepare();
    int len = left.getColumnCount();
    // set the correct expressions now
    expressions = New.arrayList();
    ArrayList<Expression> le = left.getExpressions();
    ArrayList<Expression> re = right.getExpressions();
    ColumnNamer columnNamer = new ColumnNamer(session);
    for (int i = 0; i < len; i++) {
        Expression l = le.get(i);
        Expression r = re.get(i);
        int type = Value.getHigherOrder(l.getType(), r.getType());
        long prec = Math.max(l.getPrecision(), r.getPrecision());
        int scale = Math.max(l.getScale(), r.getScale());
        int displaySize = Math.max(l.getDisplaySize(), r.getDisplaySize());
        String columnName = columnNamer.getColumnName(l, i, l.getAlias());
        Column col = new Column(columnName, type, prec, scale, displaySize);
        Expression e = new ExpressionColumn(session.getDatabase(), col);
        expressions.add(e);
    }
    if (orderList != null) {
        initOrder(session, expressions, null, orderList, getColumnCount(), true, null);
        sort = prepareOrder(orderList, expressions.size());
        orderList = null;
    }
    expressionArray = expressions.toArray(new Expression[0]);
}

Example 23 with ExpressionColumn

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

the class CompareLike method createIndexConditions.

@Override
public void createIndexConditions(Session session, TableFilter filter) {
    if (regexp) {
        return;
    }
    if (!(left instanceof ExpressionColumn)) {
        return;
    }
    ExpressionColumn l = (ExpressionColumn) left;
    if (filter != l.getTableFilter()) {
        return;
    }
    // which may be slower (possibly not in this case)
    if (!right.isEverything(ExpressionVisitor.INDEPENDENT_VISITOR)) {
        return;
    }
    if (escape != null && !escape.isEverything(ExpressionVisitor.INDEPENDENT_VISITOR)) {
        return;
    }
    String p = right.getValue(session).getString();
    if (!isInit) {
        Value e = escape == null ? null : escape.getValue(session);
        if (e == ValueNull.INSTANCE) {
            // should already be optimized
            DbException.throwInternalError();
        }
        initPattern(p, getEscapeChar(e));
    }
    if (invalidPattern) {
        return;
    }
    if (patternLength <= 0 || patternTypes[0] != MATCH) {
        // can't use an index
        return;
    }
    int dataType = l.getColumn().getType();
    if (dataType != Value.STRING && dataType != Value.STRING_IGNORECASE && dataType != Value.STRING_FIXED) {
        // column is not a varchar - can't use the index
        return;
    }
    // Get the MATCH prefix and see if we can create an index condition from
    // that.
    int maxMatch = 0;
    StringBuilder buff = new StringBuilder();
    while (maxMatch < patternLength && patternTypes[maxMatch] == MATCH) {
        buff.append(patternChars[maxMatch++]);
    }
    String begin = buff.toString();
    if (maxMatch == patternLength) {
        filter.addIndexCondition(IndexCondition.get(Comparison.EQUAL, l, ValueExpression.get(ValueString.get(begin))));
    } else {
        // TODO check if this is correct according to Unicode rules
        // (code points)
        String end;
        if (begin.length() > 0) {
            filter.addIndexCondition(IndexCondition.get(Comparison.BIGGER_EQUAL, l, ValueExpression.get(ValueString.get(begin))));
            char next = begin.charAt(begin.length() - 1);
            // that is higher)
            for (int i = 1; i < 2000; i++) {
                end = begin.substring(0, begin.length() - 1) + (char) (next + i);
                if (compareMode.compareString(begin, end, ignoreCase) == -1) {
                    filter.addIndexCondition(IndexCondition.get(Comparison.SMALLER, l, ValueExpression.get(ValueString.get(end))));
                    break;
                }
            }
        }
    }
}

Example 24 with ExpressionColumn

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

the class Comparison method optimize.

@Override
public Expression optimize(Session session) {
    left = left.optimize(session);
    if (right != null) {
        right = right.optimize(session);
        if (right instanceof ExpressionColumn) {
            if (left.isConstant() || left instanceof Parameter) {
                Expression temp = left;
                left = right;
                right = temp;
                compareType = getReversedCompareType(compareType);
            }
        }
        if (left instanceof ExpressionColumn) {
            if (right.isConstant()) {
                Value r = right.getValue(session);
                if (r == ValueNull.INSTANCE) {
                    if ((compareType & NULL_SAFE) == 0) {
                        return ValueExpression.getNull();
                    }
                }
                int colType = left.getType();
                int constType = r.getType();
                int resType = Value.getHigherOrder(colType, constType);
                // once.
                if (constType != resType) {
                    Column column = ((ExpressionColumn) left).getColumn();
                    right = ValueExpression.get(r.convertTo(resType, MathUtils.convertLongToInt(left.getPrecision()), session.getDatabase().getMode(), column, column.getEnumerators()));
                }
            } else if (right instanceof Parameter) {
                ((Parameter) right).setColumn(((ExpressionColumn) left).getColumn());
            }
        }
    }
    if (compareType == IS_NULL || compareType == IS_NOT_NULL) {
        if (left.isConstant()) {
            return ValueExpression.get(getValue(session));
        }
    } else {
        if (SysProperties.CHECK && (left == null || right == null)) {
            DbException.throwInternalError(left + " " + right);
        }
        if (left == ValueExpression.getNull() || right == ValueExpression.getNull()) {
            // a NULL constants
            if ((compareType & NULL_SAFE) == 0) {
                return ValueExpression.getNull();
            }
        }
        if (left.isConstant() && right.isConstant()) {
            return ValueExpression.get(getValue(session));
        }
    }
    return this;
}

Example 25 with ExpressionColumn

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

the class Aggregate method getMinMaxColumnIndex.

private Index getMinMaxColumnIndex() {
    if (on instanceof ExpressionColumn) {
        ExpressionColumn col = (ExpressionColumn) on;
        Column column = col.getColumn();
        TableFilter filter = col.getTableFilter();
        if (filter != null) {
            Table table = filter.getTable();
            return table.getIndexForColumn(column, true, false);
        }
    }
    return null;
}