/*
* Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (http://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.jaqu;
import org.h2.jaqu.util.ClassUtils;
/**
* This class provides static methods that represents common SQL functions.
*/
public class Function implements Token {
// must be a new instance
private static final Long COUNT_STAR = Long.valueOf(0);
protected Object[] x;
private final String name;
protected Function(String name, Object... x) {
this.name = name;
this.x = x;
}
@Override
public <T> void appendSQL(SQLStatement stat, Query<T> query) {
stat.appendSQL(name).appendSQL("(");
int i = 0;
for (Object o : x) {
if (i++ > 0) {
stat.appendSQL(",");
}
query.appendSQL(stat, o);
}
stat.appendSQL(")");
}
public static Long count() {
return COUNT_STAR;
}
public static Integer length(Object x) {
return Db.registerToken(
ClassUtils.newObject(Integer.class), new Function("LENGTH", x));
}
@SuppressWarnings("unchecked")
public static <T extends Number> T sum(T x) {
return (T) Db.registerToken(
ClassUtils.newObject(x.getClass()), new Function("SUM", x));
}
public static Long count(Object x) {
return Db.registerToken(
ClassUtils.newObject(Long.class), new Function("COUNT", x));
}
public static Boolean isNull(Object x) {
return Db.registerToken(
ClassUtils.newObject(Boolean.class), new Function("", x) {
@Override
public <T> void appendSQL(SQLStatement stat, Query<T> query) {
query.appendSQL(stat, x[0]);
stat.appendSQL(" IS NULL");
}
});
}
public static Boolean isNotNull(Object x) {
return Db.registerToken(
ClassUtils.newObject(Boolean.class), new Function("", x) {
@Override
public <T> void appendSQL(SQLStatement stat, Query<T> query) {
query.appendSQL(stat, x[0]);
stat.appendSQL(" IS NOT NULL");
}
});
}
public static Boolean not(Boolean x) {
return Db.registerToken(
ClassUtils.newObject(Boolean.class), new Function("", x) {
@Override
public <T> void appendSQL(SQLStatement stat, Query<T> query) {
stat.appendSQL("NOT ");
query.appendSQL(stat, x[0]);
}
});
}
public static Boolean or(Boolean... x) {
return Db.registerToken(
ClassUtils.newObject(Boolean.class),
new Function("", (Object[]) x) {
@Override
public <T> void appendSQL(SQLStatement stat, Query<T> query) {
int i = 0;
for (Object o : x) {
if (i++ > 0) {
stat.appendSQL(" OR ");
}
query.appendSQL(stat, o);
}
}
});
}
public static Boolean and(Boolean... x) {
return Db.registerToken(
ClassUtils.newObject(Boolean.class),
new Function("", (Object[]) x) {
@Override
public <T> void appendSQL(SQLStatement stat, Query<T> query) {
int i = 0;
for (Object o : x) {
if (i++ > 0) {
stat.appendSQL(" AND ");
}
query.appendSQL(stat, o);
}
}
});
}
@SuppressWarnings("unchecked")
public static <X> X min(X x) {
Class<X> clazz = (Class<X>) x.getClass();
X o = ClassUtils.newObject(clazz);
return Db.registerToken(o, new Function("MIN", x));
}
@SuppressWarnings("unchecked")
public static <X> X max(X x) {
Class<X> clazz = (Class<X>) x.getClass();
X o = ClassUtils.newObject(clazz);
return Db.registerToken(o, new Function("MAX", x));
}
public static Boolean like(String x, String pattern) {
Boolean o = ClassUtils.newObject(Boolean.class);
return Db.registerToken(o, new Function("LIKE", x, pattern) {
@Override
public <T> void appendSQL(SQLStatement stat, Query<T> query) {
stat.appendSQL("(");
query.appendSQL(stat, x[0]);
stat.appendSQL(" LIKE ");
query.appendSQL(stat, x[1]);
stat.appendSQL(")");
}
});
}
}