org.aksw.sparqlify.algebra.sql.nodes

Interface SqlOp

All Known Implementing Classes:

SqlOpBase, SqlOpBase0, SqlOpBase1, SqlOpBase2, SqlOpBaseN, SqlOpDistinct, SqlOpEmpty, SqlOpExtend, SqlOpFilter, SqlOpFilterExpr, SqlOpGroupBy, SqlOpJoin, SqlOpJoinN, SqlOpLeaf, SqlOpOrder, SqlOpProject, SqlOpQuery, SqlOpRename, SqlOpSelectBlock, SqlOpSlice, SqlOpTable, SqlOpUnionN

public interface SqlOp

An SqlNode corresponds to an operator in the relational algebra. Each SqlNode owns a (immutable) description of its corresponding schema.

Author:

Claus Stadler

Method Summary

Modifier and Type	Method and Description
SqlOp	copy(Schema schema, List<SqlOp> newOps) Create a copy of the SqlOp with a projected schema.
Schema	getSchema()
List<SqlOp>	getSubOps()
boolean	isEmpty()
void	write(org.apache.jena.atlas.io.IndentedWriter writer)

Method Detail

getSchema

Schema getSchema()

isEmpty

boolean isEmpty()

getSubOps

List<SqlOp> getSubOps()

write

void write(org.apache.jena.atlas.io.IndentedWriter writer)

copy

SqlOp copy(Schema schema,
           List<SqlOp> newOps)

Create a copy of the SqlOp with a projected schema. The new schema will only hold information of the selected columns. Used to filter an Op to only the referenced columns. This is different from a projection!