use of com.yahoo.elide.datastores.aggregation.annotation.JoinType in project elide by yahoo.
the class JoinExpressionExtractor method visitJoinReference.
@Override
public Set<String> visitJoinReference(JoinReference reference) {
JoinPath joinPath = reference.getPath();
List<PathElement> pathElements = joinPath.getPathElements();
ColumnContext currentCtx = this.context;
for (int i = 0; i < pathElements.size() - 1; i++) {
PathElement pathElement = pathElements.get(i);
Type<?> joinClass = pathElement.getFieldType();
String joinFieldName = pathElement.getFieldName();
SQLJoin sqlJoin = currentCtx.getQueryable().getJoin(joinFieldName);
ColumnContext joinCtx;
String onClause;
JoinType joinType;
String fullExpression;
if (sqlJoin != null) {
joinType = sqlJoin.getJoinType();
joinCtx = (ColumnContext) currentCtx.get(joinFieldName);
if (joinType.equals(JoinType.CROSS)) {
onClause = EMPTY;
} else {
onClause = ON + currentCtx.resolve(sqlJoin.getJoinExpression());
}
} else {
joinType = JoinType.LEFT;
SQLTable table = metaDataStore.getTable(joinClass);
joinCtx = ColumnContext.builder().queryable(table).alias(appendAlias(currentCtx.getAlias(), joinFieldName)).metaDataStore(currentCtx.getMetaDataStore()).column(currentCtx.getColumn()).tableArguments(mergedArgumentMap(table.getArguments(), currentCtx.getTableArguments())).build();
onClause = ON + String.format("%s.%s = %s.%s", currentCtx.getAlias(), dictionary.getAnnotatedColumnName(pathElement.getType(), joinFieldName), joinCtx.getAlias(), dictionary.getAnnotatedColumnName(joinClass, dictionary.getIdFieldName(joinClass)));
}
SQLDialect sqlDialect = currentCtx.getQueryable().getDialect();
String joinAlias = applyQuotes(joinCtx.getAlias(), sqlDialect);
String joinKeyword = currentCtx.getQueryable().getDialect().getJoinKeyword(joinType);
String joinSource = constructTableOrSubselect(joinCtx, joinClass);
if (sqlDialect.useASBeforeTableAlias()) {
fullExpression = String.format("%s %s AS %s %s", joinKeyword, joinSource, joinAlias, onClause);
} else {
fullExpression = String.format("%s %s %s %s", joinKeyword, joinSource, joinAlias, onClause);
}
joinExpressions.add(fullExpression);
/**
* If this `for` loop runs more than once, context should be switched to join context.
*/
currentCtx = joinCtx;
}
// If reference within current join reference is of type PhysicalReference, then below visitor doesn't matter.
// If it is of type LogicalReference, then visitLogicalReference method will recreate visitor with correct
// value of ColumnProjection in context.
JoinExpressionExtractor visitor = new JoinExpressionExtractor(currentCtx);
joinExpressions.addAll(reference.getReference().accept(visitor));
return joinExpressions;
}
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