Interface SqlValidatorScope

All Known Subinterfaces:
AggregatingScope
All Known Implementing Classes:
AggregatingSelectScope, DelegatingScope, GroupByScope, JoinScope, ListScope, MatchRecognizeScope, OrderByScope, OverScope, ParameterScope, PivotScope, SelectScope, UnpivotScope

public interface SqlValidatorScope
Name-resolution scope. Represents any position in a parse tree than an expression can be, or anything in the parse tree which has columns.

When validating an expression, say "foo"."bar", you first use the resolve(java.util.List<java.lang.String>, org.apache.calcite.sql.validate.SqlNameMatcher, boolean, org.apache.calcite.sql.validate.SqlValidatorScope.Resolved) method of the scope where the expression is defined to locate "foo". If successful, this returns a namespace describing the type of the resulting object.

  • Method Details

    • getValidator

      SqlValidator getValidator()
      Returns the validator which created this scope.
    • getNode

      SqlNode getNode()
      Returns the root node of this scope. Never null.
    • resolve

      void resolve(List<String> names, SqlNameMatcher nameMatcher, boolean deep, SqlValidatorScope.Resolved resolved)
      Looks up a node with a given name. Returns null if none is found.
      Parameters:
      names - Name of node to find, maybe partially or fully qualified
      nameMatcher - Name matcher
      deep - Whether to look more than one level deep
      resolved - Callback wherein to write the match(es) we find
    • findQualifyingTableName

      @Deprecated Pair<String,SqlValidatorNamespace> findQualifyingTableName(String columnName, SqlNode ctx)
    • findQualifyingTableNames

      Map<String,org.apache.calcite.sql.validate.ScopeChild> findQualifyingTableNames(String columnName, SqlNode ctx, SqlNameMatcher nameMatcher)
      Finds all table aliases which are implicitly qualifying an unqualified column name.

      This method is only implemented in scopes (such as SelectScope) which can be the context for name-resolution. In scopes such as IdentifierNamespace, it throws UnsupportedOperationException.

      Parameters:
      columnName - Column name
      ctx - Validation context, to appear in any error thrown
      nameMatcher - Name matcher
      Returns:
      Map of applicable table alias and namespaces, never null, empty if no aliases found
    • findAllColumnNames

      void findAllColumnNames(List<SqlMoniker> result)
      Collects the SqlMonikers of all possible columns in this scope.
      Parameters:
      result - an array list of strings to add the result to
    • findAliases

      void findAliases(Collection<SqlMoniker> result)
      Collects the SqlMonikers of all table aliases (uses of tables in query FROM clauses) available in this scope.
      Parameters:
      result - a list of monikers to add the result to
    • fullyQualify

      SqlQualified fullyQualify(SqlIdentifier identifier)
      Converts an identifier into a fully-qualified identifier. For example, the "empno" in "select empno from emp natural join dept" becomes "emp.empno".
      Returns:
      A qualified identifier, never null
    • addChild

      void addChild(SqlValidatorNamespace ns, String alias, boolean nullable)
      Registers a relation in this scope.
      Parameters:
      ns - Namespace representing the result-columns of the relation
      alias - Alias with which to reference the relation, must not be null
      nullable - Whether this is a null-generating side of a join
    • lookupWindow

      @Nullable SqlWindow lookupWindow(String name)
      Finds a window with a given name. Returns null if not found.
    • getMonotonicity

      SqlMonotonicity getMonotonicity(SqlNode expr)
      Returns whether an expression is monotonic in this scope. For example, if the scope has previously been sorted by columns X, Y, then X is monotonic in this scope, but Y is not.
    • getOrderList

      @Nullable SqlNodeList getOrderList()
      Returns the expressions by which the rows in this scope are sorted. If the rows are unsorted, returns null.
    • resolveColumn

      @Nullable RelDataType resolveColumn(String name, SqlNode ctx)
      Resolves a single identifier to a column, and returns the datatype of that column.

      If it cannot find the column, returns null. If the column is ambiguous, throws an error with context ctx.

      Parameters:
      name - Name of column
      ctx - Context for exception
      Returns:
      Type of column, if found and unambiguous; null if not found
    • getOperandScope

      SqlValidatorScope getOperandScope(SqlCall call)
      Returns the scope within which operands to a call are to be validated. Usually it is this scope, but when the call is to an aggregate function and this is an aggregating scope, it will be a a different scope.
      Parameters:
      call - Call
      Returns:
      Scope within which to validate arguments to call.
    • validateExpr

      void validateExpr(SqlNode expr)
      Performs any scope-specific validation of an expression. For example, an aggregating scope requires that expressions are valid aggregations. The expression has already been validated.
    • getTableNamespace

      @Deprecated @Nullable SqlValidatorNamespace getTableNamespace(List<String> names)
    • resolveTable

      void resolveTable(List<String> names, SqlNameMatcher nameMatcher, SqlValidatorScope.Path path, SqlValidatorScope.Resolved resolved)
      Looks up a table in this scope from its name. If found, calls resolve(List, SqlNameMatcher, boolean, Resolved). TableNamespace that wraps it. If the "table" is defined in a WITH clause it may be a query, not a table after all.

      The name matcher is not null, and one typically uses SqlValidatorCatalogReader.nameMatcher().

      Parameters:
      names - Name of table, may be qualified or fully-qualified
      nameMatcher - Name matcher
      path - List of names that we have traversed through so far
    • nullifyType

      RelDataType nullifyType(SqlNode node, RelDataType type)
      Converts the type of an expression to nullable, if the context warrants it.
    • isWithin

      default boolean isWithin(@Nullable SqlValidatorScope scope2)
      Returns whether this scope is enclosed within scope2 in such a way that it can see the contents of scope2.