In-Criterion的Ignorecase

Question

我想用带有Hibernate Criteria API的In-Criteria来选择不区分大小写的项目。例如。

Criteria crit = session.createCriteria(Item.class);
crit.add(Restrictions.in("prop", valueList).ignoreCase());

不幸的是，Criterion类没有ignoreCase方法。HQL不是一种替代方案。

Answer 1

获取Restrictions.in() (InExpression)返回的Criterion类的源代码，创建另一个类似的类，但将值列表中的所有元素转换为小写，并生成如下SQL查询：

lower(prop) in (...)

Answer 2

我实现了自己的InExpression，它忽略了大小写。它与hibernate-core-3.6.10中的InExpresion几乎相同。唯一的区别是“较低的(..)”。

import java.util.ArrayList;
import org.hibernate.Criteria;
import org.hibernate.EntityMode;
import org.hibernate.HibernateException;
import org.hibernate.criterion.CriteriaQuery;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.InExpression;
import org.hibernate.engine.TypedValue;
import org.hibernate.type.CompositeType;
import org.hibernate.type.Type;
import org.hibernate.util.StringHelper;

public class InExpressionIgnoringCase implements Criterion {

private final String propertyName;
private final Object[] values;

public InExpressionIgnoringCase(final String propertyName, final Object[] values) {
    this.propertyName = propertyName;
    this.values = values;
}

public String toSqlString(final Criteria criteria, final CriteriaQuery criteriaQuery) throws HibernateException {
    final String[] columns = criteriaQuery.findColumns(this.propertyName, criteria);
    final String[] wrappedLowerColumns = wrapLower(columns);
    if (criteriaQuery.getFactory().getDialect().supportsRowValueConstructorSyntaxInInList() || columns.length <= 1) {

        String singleValueParam = StringHelper.repeat("lower(?), ", columns.length - 1) + "lower(?)";
        if (columns.length > 1)
            singleValueParam = '(' + singleValueParam + ')';
        final String params = this.values.length > 0 ? StringHelper.repeat(singleValueParam + ", ",
                this.values.length - 1) + singleValueParam : "";
        String cols = StringHelper.join(", ", wrappedLowerColumns);
        if (columns.length > 1)
            cols = '(' + cols + ')';
        return cols + " in (" + params + ')';
    } else {
        String cols = " ( " + StringHelper.join(" = lower(?) and ", wrappedLowerColumns) + "= lower(?) ) ";
        cols = this.values.length > 0 ? StringHelper.repeat(cols + "or ", this.values.length - 1) + cols : "";
        cols = " ( " + cols + " ) ";
        return cols;
    }
}

public TypedValue[] getTypedValues(final Criteria criteria, final CriteriaQuery criteriaQuery)
        throws HibernateException {
    final ArrayList<TypedValue> list = new ArrayList<TypedValue>();
    final Type type = criteriaQuery.getTypeUsingProjection(criteria, this.propertyName);
    if (type.isComponentType()) {
        final CompositeType actype = (CompositeType) type;
        final Type[] types = actype.getSubtypes();
        for (int j = 0; j < this.values.length; j++) {
            for (int i = 0; i < types.length; i++) {
                final Object subval = this.values[j] == null ? null : actype.getPropertyValues(this.values[j],
                        EntityMode.POJO)[i];
                list.add(new TypedValue(types[i], subval, EntityMode.POJO));
            }
        }
    } else {
        for (int j = 0; j < this.values.length; j++) {
            list.add(new TypedValue(type, this.values[j], EntityMode.POJO));
        }
    }
    return list.toArray(new TypedValue[list.size()]);
}

@Override
public String toString() {
    return this.propertyName + " in (" + StringHelper.toString(this.values) + ')';
}

private String[] wrapLower(final String[] columns) {
    final String[] wrappedColumns = new String[columns.length];
    for (int i = 0; i < columns.length; i++) {
        wrappedColumns[i] = "lower(" + columns[i] + ")";
    }
    return wrappedColumns;
}
}

用法：

final Criteria crit = session.createCriteria(Item.class);
            crit.add(new InExpressionIgnoringCase("prop", array));

Answer 3

另一种方法是使用sqlRestriction。因此，您将值转换为逗号分隔的小写字符串，然后调用。

crit.add(Restrictions.sqlRestriction("lower({alias}.prop) in ( " + q + " )"));

但是，您的查询参数必须进行清理。

您也可以使用disjunction。

Junction j = Restrictions.disjunction();
for (String prop: props) {
    j.add(Restrictions.eq("prop", prop).ignoreCase());
}
crit.add(j);