org.apache.calcite.sql.validate

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.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	SqlValidatorScope.EmptyPath A path that has no steps.
static class	SqlValidatorScope.Path A sequence of steps by which an identifier was resolved.
static class	SqlValidatorScope.Resolve A match found when looking up a name.
static interface	SqlValidatorScope.Resolved Callback from resolve(java.util.List<java.lang.String>, org.apache.calcite.sql.validate.SqlNameMatcher, boolean, org.apache.calcite.sql.validate.SqlValidatorScope.Resolved).
static class	SqlValidatorScope.ResolvedImpl Default implementation of SqlValidatorScope.Resolved.
static class	SqlValidatorScope.Step A step in resolving an identifier.

Method Summary

Modifier and Type	Method and Description
void	addChild(SqlValidatorNamespace ns, String alias, boolean nullable) Registers a relation in this scope.
void	findAliases(Collection<SqlMoniker> result) Collects the SqlMonikers of all table aliases (uses of tables in query FROM clauses) available in this scope.
void	findAllColumnNames(List<SqlMoniker> result) Collects the SqlMonikers of all possible columns in this scope.
Pair<String,SqlValidatorNamespace>	findQualifyingTableName(String columnName, SqlNode ctx) Deprecated. Use findQualifyingTableNames(String, SqlNode, SqlNameMatcher)
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.
SqlQualified	fullyQualify(SqlIdentifier identifier) Converts an identifier into a fully-qualified identifier.
SqlMonotonicity	getMonotonicity(SqlNode expr) Returns whether an expression is monotonic in this scope.
SqlNode	getNode() Returns the root node of this scope.
SqlValidatorScope	getOperandScope(SqlCall call) Returns the scope within which operands to a call are to be validated.
@Nullable SqlNodeList	getOrderList() Returns the expressions by which the rows in this scope are sorted.
@Nullable SqlValidatorNamespace	getTableNamespace(List<String> names) Deprecated. Use resolveTable(List, SqlNameMatcher, Path, Resolved).
SqlValidator	getValidator() Returns the validator which created this scope.
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.
@Nullable SqlWindow	lookupWindow(String name) Finds a window with a given name.
RelDataType	nullifyType(SqlNode node, RelDataType type) Converts the type of an expression to nullable, if the context warrants it.
void	resolve(List<String> names, SqlNameMatcher nameMatcher, boolean deep, SqlValidatorScope.Resolved resolved) Looks up a node with a given name.
@Nullable RelDataType	resolveColumn(String name, SqlNode ctx) Resolves a single identifier to a column, and returns the datatype of that column.
void	resolveTable(List<String> names, SqlNameMatcher nameMatcher, SqlValidatorScope.Path path, SqlValidatorScope.Resolved resolved) Looks up a table in this scope from its name.
void	validateExpr(SqlNode expr) Performs any scope-specific validation of an expression.

Method Detail

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)

Deprecated. Use findQualifyingTableNames(String, SqlNode, SqlNameMatcher)

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)

Deprecated. Use resolveTable(List, SqlNameMatcher, Path, Resolved).

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.