/** 如果是1 = id的情况，转化为id = 1 */
private static IFilter exchage(IFilter root) {
IBooleanFilter bf = (IBooleanFilter) root;
if (!FilterUtils.isConstValue(bf.getValue()) && FilterUtils.isConstValue(bf.getColumn())) {
Object val = bf.getColumn();
bf.setColumn(bf.getValue());
bf.setValue(val);
OPERATION newOp = bf.getOperation();
switch (bf.getOperation()) {
case GT:
newOp = OPERATION.LT;
break;
case LT:
newOp = OPERATION.GT;
break;
case GT_EQ:
newOp = OPERATION.LT_EQ;
break;
case LT_EQ:
newOp = OPERATION.GT_EQ;
break;
default:
break;
}
bf.setOperation(newOp);
}
return bf;
}
/** 将0=1/1=1/true的恒等式进行优化 */
private static IFilter shortestFilter(IFilter root) throws EmptyResultFilterException {
IFilter filter = FilterUtils.toDNFAndFlat(root);
List<List<IFilter>> DNFfilter = FilterUtils.toDNFNodesArray(filter);
List<List<IFilter>> newDNFfilter = new ArrayList<List<IFilter>>();
for (List<IFilter> andDNFfilter : DNFfilter) {
boolean isShortest = false;
List<IFilter> newAndDNFfilter = new ArrayList<IFilter>();
for (IFilter one : andDNFfilter) {
if (one.getOperation() == OPERATION.CONSTANT) {
boolean flag = false;
if (((IBooleanFilter) one).getColumn() instanceof ISelectable) { // 可能是个not函数
newAndDNFfilter.add(one); // 不能丢弃
} else {
String value = ((IBooleanFilter) one).getColumn().toString();
if (StringUtils.isNumeric(value)) {
flag = BooleanUtils.toBoolean(Integer.valueOf(value));
} else {
flag = BooleanUtils.toBoolean(((IBooleanFilter) one).getColumn().toString());
}
if (!flag) {
isShortest = true;
break;
}
}
} else {
newAndDNFfilter.add(one);
}
}
if (!isShortest) {
if (newAndDNFfilter.isEmpty()) {
// 代表出现为true or xxx，直接返回true
IBooleanFilter f = ASTNodeFactory.getInstance().createBooleanFilter();
f.setOperation(OPERATION.CONSTANT);
f.setColumn("1");
f.setColumnName(ObjectUtils.toString("1"));
return f;
} else { // 针对非false的情况
newDNFfilter.add(newAndDNFfilter);
}
}
}
if (newDNFfilter.isEmpty()) {
throw new EmptyResultFilterException("空结果");
}
return FilterUtils.DNFToOrLogicTree(newDNFfilter);
}
private static void findBooleanFilter(IBooleanFilter filter, Parameters parameters) {
if (filter == null) {
return;
}
findObject(filter.getColumn(), parameters);
findObject(filter.getValue(), parameters);
if (filter.getOperation() == OPERATION.IN) {
List<Object> values = filter.getValues();
if (values != null && !values.isEmpty()) {
for (int i = 0; i < values.size(); i++) {
findObject(values.get(i), parameters);
}
}
}
}
/**
* 构造Range对象
*
* @param f
* @return
*/
protected Range getRange(IBooleanFilter f) {
DataType type = getColumn(f).getDataType();
if (type == null) {
type = DataTypeUtil.getTypeOfObject(f.getValue());
}
switch (f.getOperation()) {
case EQ:
return new Range(null, type, getValue(f), getValue(f));
case GT:
return new Range(null, type, getValue(f), false, null, true);
case GT_EQ:
return new Range(null, type, getValue(f), true, null, true);
case LT:
return new Range(null, type, null, true, getValue(f), false);
case LT_EQ:
return new Range(null, type, null, true, getValue(f), true);
default:
return null;
}
}
/**
* 根据range结果，构造filter
*
* @param range
* @param column
* @return
*/
protected List<IFilter> buildFilter(Range range, Object column) {
List<IFilter> filters = new ArrayList(2);
if (range == null) {
return filters;
}
if (range.isSingleValue()) {
IBooleanFilter en =
ASTNodeFactory.getInstance().createBooleanFilter().setOperation(OPERATION.EQ);
en.setColumn(column);
en.setValue(range.getMaxValue());
filters.add(en);
return filters;
}
if (range.getMinValue() != null) {
IBooleanFilter gn;
if (range.isMinIncluded()) {
gn = ASTNodeFactory.getInstance().createBooleanFilter().setOperation(OPERATION.GT_EQ);
} else {
gn = ASTNodeFactory.getInstance().createBooleanFilter().setOperation(OPERATION.GT);
}
gn.setColumn(column);
gn.setValue(range.getMinValue());
filters.add(gn);
}
if (range.getMaxValue() != null) {
IBooleanFilter ln;
if (range.isMaxIncluded()) {
ln = ASTNodeFactory.getInstance().createBooleanFilter().setOperation(OPERATION.LT_EQ);
} else {
ln = ASTNodeFactory.getInstance().createBooleanFilter().setOperation(OPERATION.LT);
}
ln.setColumn(column);
ln.setValue(range.getMaxValue());
filters.add(ln);
}
return filters;
}
protected ISelectable getColumn(IBooleanFilter f) {
return (ISelectable) f.getColumn();
}
protected Comparable getValue(IBooleanFilter f) {
return (Comparable) f.getValue();
}
private static IFilter typeConvert(IFilter root) {
IBooleanFilter bf = (IBooleanFilter) root;
// 如果是id in (xx)
if (bf.getValues() != null && bf.getColumn() instanceof ISelectable) {
for (int i = 0; i < bf.getValues().size(); i++) {
bf.getValues()
.set(
i,
OptimizerUtils.convertType(
bf.getValues().get(i), ((ISelectable) bf.getColumn()).getDataType()));
}
} else {
// 如果是 1 = id情况
if (FilterUtils.isConstValue(bf.getColumn()) && !FilterUtils.isConstValue(bf.getValue())) {
DATA_TYPE type = null;
if (bf.getValue() instanceof IColumn) {
type = ((IColumn) bf.getValue()).getDataType();
}
if (bf.getValue() instanceof IFunction) {
type = ((IFunction) bf.getValue()).getDataType();
}
bf.setColumn(OptimizerUtils.convertType(bf.getColumn(), type));
}
// 如果是 id = 1情况
if (FilterUtils.isConstValue(bf.getValue()) && !FilterUtils.isConstValue(bf.getColumn())) {
DATA_TYPE type = null;
if (bf.getColumn() instanceof IColumn) {
type = ((IColumn) bf.getColumn()).getDataType();
}
if (bf.getColumn() instanceof IFunction) {
type = ((IFunction) bf.getColumn()).getDataType();
}
bf.setValue(OptimizerUtils.convertType(bf.getValue(), type));
}
}
return bf;
}
