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Example 1 with JoinType

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;
}
Also used : JoinPath(com.yahoo.elide.datastores.aggregation.core.JoinPath) PathElement(com.yahoo.elide.core.Path.PathElement) SQLDialect(com.yahoo.elide.datastores.aggregation.queryengines.sql.dialects.SQLDialect) SQLTable(com.yahoo.elide.datastores.aggregation.queryengines.sql.metadata.SQLTable) ColumnContext(com.yahoo.elide.datastores.aggregation.metadata.ColumnContext) SQLJoin(com.yahoo.elide.datastores.aggregation.queryengines.sql.metadata.SQLJoin) JoinType(com.yahoo.elide.datastores.aggregation.annotation.JoinType)

Aggregations

PathElement (com.yahoo.elide.core.Path.PathElement)1 JoinType (com.yahoo.elide.datastores.aggregation.annotation.JoinType)1 JoinPath (com.yahoo.elide.datastores.aggregation.core.JoinPath)1 ColumnContext (com.yahoo.elide.datastores.aggregation.metadata.ColumnContext)1 SQLDialect (com.yahoo.elide.datastores.aggregation.queryengines.sql.dialects.SQLDialect)1 SQLJoin (com.yahoo.elide.datastores.aggregation.queryengines.sql.metadata.SQLJoin)1 SQLTable (com.yahoo.elide.datastores.aggregation.queryengines.sql.metadata.SQLTable)1