@Override
public void meet(FunctionCall fc) throws RuntimeException {
// special optimizations for frequent cases with variables
if ((XMLSchema.DOUBLE.toString().equals(fc.getURI())
|| XMLSchema.FLOAT.toString().equals(fc.getURI()))
&& fc.getArgs().size() == 1) {
optypes.push(ValueType.DOUBLE);
fc.getArgs().get(0).visit(this);
optypes.pop();
} else if ((XMLSchema.INTEGER.toString().equals(fc.getURI())
|| XMLSchema.INT.toString().equals(fc.getURI()))
&& fc.getArgs().size() == 1) {
optypes.push(ValueType.INT);
fc.getArgs().get(0).visit(this);
optypes.pop();
} else if (XMLSchema.BOOLEAN.toString().equals(fc.getURI()) && fc.getArgs().size() == 1) {
optypes.push(ValueType.BOOL);
fc.getArgs().get(0).visit(this);
optypes.pop();
} else if (XMLSchema.DATE.toString().equals(fc.getURI()) && fc.getArgs().size() == 1) {
optypes.push(ValueType.DATE);
fc.getArgs().get(0).visit(this);
optypes.pop();
} else {
String fnUri = fc.getURI();
String[] args = new String[fc.getArgs().size()];
NativeFunction nf = functionRegistry.get(fnUri);
if (nf != null && nf.isSupported(parent.getDialect())) {
for (int i = 0; i < args.length; i++) {
args[i] =
new ValueExpressionEvaluator(fc.getArgs().get(i), parent, nf.getArgumentType(i))
.build();
}
if (optypes.peek() != nf.getReturnType()) {
builder.append(castExpression(nf.getNative(parent.getDialect(), args), optypes.peek()));
} else {
builder.append(nf.getNative(parent.getDialect(), args));
}
} else {
throw new IllegalArgumentException(
"the function " + fnUri + " is not supported by the SQL translation");
}
}
}
@Override
public void meet(MathExpr expr) throws RuntimeException {
ValueType ot = new OPTypeFinder(expr).coerce();
if (ot == ValueType.STRING) {
if (expr.getOperator() == MathExpr.MathOp.PLUS) {
builder.append(
functionRegistry
.get(FN.CONCAT.stringValue())
.getNative(
parent.getDialect(),
new ValueExpressionEvaluator(expr.getLeftArg(), parent, ot).build(),
new ValueExpressionEvaluator(expr.getRightArg(), parent, ot).build()));
} else {
throw new IllegalArgumentException(
"operation " + expr.getOperator() + " is not supported on strings");
}
} else {
if (ot == ValueType.NODE || ot == ValueType.TERM) {
ot = ValueType.DOUBLE;
}
optypes.push(ot);
expr.getLeftArg().visit(this);
builder.append(getSQLOperator(expr.getOperator()));
expr.getRightArg().visit(this);
optypes.pop();
}
}
@Override
public void meet(If node) throws RuntimeException {
builder.append("CASE WHEN ");
optypes.push(ValueType.BOOL);
node.getCondition().visit(this);
optypes.pop();
optypes.push(new OPTypeFinder(node).coerce());
builder.append(" THEN ");
node.getResult().visit(this);
builder.append(" ELSE ");
node.getAlternative().visit(this);
builder.append(" END");
optypes.pop();
}
@Override
public void meet(Count node) throws RuntimeException {
builder.append("COUNT(");
if (node.isDistinct()) {
builder.append("DISTINCT ");
}
if (node.getArg() == null) {
// this is a weird special case where we need to expand to all variables selected in the query
// wrapped
// by the group; we cannot simply use "*" because the concept of variables is a different one
// in SQL,
// so instead we construct an ARRAY of the bindings of all variables
List<String> countVariables = new ArrayList<>();
for (SQLVariable v : parent.getVariables().values()) {
if (v.getProjectionType() == ValueType.NONE) {
Preconditions.checkState(
v.getExpressions().size() > 0, "no expressions available for variable");
countVariables.add(v.getExpressions().get(0));
}
}
builder.append("ARRAY[");
Joiner.on(',').appendTo(builder, countVariables);
builder.append("]");
} else {
optypes.push(ValueType.NODE);
node.getArg().visit(this);
optypes.pop();
}
builder.append(")");
}
@Override
public void meet(Sum node) throws RuntimeException {
builder.append("SUM(");
optypes.push(ValueType.DOUBLE);
node.getArg().visit(this);
optypes.pop();
builder.append(")");
}
@Override
public void meet(Compare cmp) throws RuntimeException {
optypes.push(new OPTypeFinder(cmp).coerce());
cmp.getLeftArg().visit(this);
builder.append(getSQLOperator(cmp.getOperator()));
cmp.getRightArg().visit(this);
optypes.pop();
}
@Override
public void meet(SameTerm cmp) throws RuntimeException {
// covered by value binding in variables
optypes.push(ValueType.TERM);
cmp.getLeftArg().visit(this);
builder.append(" = ");
cmp.getRightArg().visit(this);
optypes.pop();
}
public ValueExpressionEvaluator(ValueExpr expr, SQLBuilder parent, ValueType optype) {
this.parent = parent;
optypes.push(optype);
if (log.isTraceEnabled()) {
long start = System.currentTimeMillis();
expr.visit(this);
log.trace("expression evaluated in {} ms", (System.currentTimeMillis() - start));
} else {
expr.visit(this);
}
}
@Override
public void meet(Bound node) throws RuntimeException {
ValueExpr arg = node.getArg();
if (arg instanceof ValueConstant) {
builder.append(Boolean.toString(true));
} else if (arg instanceof Var) {
builder.append("(");
optypes.push(ValueType.NODE);
arg.visit(this);
optypes.pop();
builder.append(" IS NOT NULL)");
}
}
@Override
public void meet(BNodeGenerator gen) throws RuntimeException {
if (gen.getNodeIdExpr() != null) {
// get value of argument and express it as string
optypes.push(ValueType.STRING);
gen.getNodeIdExpr().visit(this);
optypes.pop();
} else {
builder
.append("'")
.append(
Long.toHexString(System.currentTimeMillis())
+ Integer.toHexString(anonIdGenerator.nextInt(1000)))
.append("'");
}
}
@Override
public void meet(Like node) throws RuntimeException {
if (node.isCaseSensitive()) {
optypes.push(ValueType.STRING);
node.getArg().visit(this);
optypes.pop();
builder.append(" LIKE ");
node.getPattern();
} else {
builder.append(
parent
.getDialect()
.getILike(
new ValueExpressionEvaluator(node.getArg(), parent, ValueType.STRING).build(),
node.getOpPattern()));
}
}
@Override
public void meet(IRIFunction fun) throws RuntimeException {
if (fun.getBaseURI() != null) {
String ex = new ValueExpressionEvaluator(fun.getArg(), parent, ValueType.STRING).build();
builder
.append("CASE WHEN position(':' IN ")
.append(ex)
.append(") > 0 THEN ")
.append(ex)
.append(" ELSE ")
.append(
functionRegistry
.get(FN.CONCAT.stringValue())
.getNative(parent.getDialect(), "'" + fun.getBaseURI() + "'", ex))
.append(" END ");
} else {
// get value of argument and express it as string
optypes.push(ValueType.STRING);
fun.getArg().visit(this);
optypes.pop();
}
}
@Override
public void meet(Str node) throws RuntimeException {
optypes.push(ValueType.STRING);
node.getArg().visit(this);
optypes.pop();
}