github.com/cockroachdb/cockroach@v20.2.0-alpha.1+incompatible/pkg/sql/opt/testutils/testcat/vtable.go (about)

     1  // Copyright 2018 The Cockroach Authors.
     2  //
     3  // Use of this software is governed by the Business Source License
     4  // included in the file licenses/BSL.txt.
     5  //
     6  // As of the Change Date specified in that file, in accordance with
     7  // the Business Source License, use of this software will be governed
     8  // by the Apache License, Version 2.0, included in the file
     9  // licenses/APL.txt.
    10  
    11  package testcat
    12  
    13  import (
    14  	"github.com/cockroachdb/cockroach/pkg/sql/parser"
    15  	"github.com/cockroachdb/cockroach/pkg/sql/sem/tree"
    16  	"github.com/cockroachdb/cockroach/pkg/sql/vtable"
    17  	"github.com/cockroachdb/errors"
    18  )
    19  
    20  var informationSchemaMap = map[string]*tree.CreateTable{}
    21  
    22  var informationSchemaTables = []string{
    23  	vtable.InformationSchemaColumns,
    24  	vtable.InformationSchemaAdministrableRoleAuthorizations,
    25  	vtable.InformationSchemaApplicableRoles,
    26  	vtable.InformationSchemaColumnPrivileges,
    27  	vtable.InformationSchemaSchemata,
    28  	vtable.InformationSchemaTables,
    29  }
    30  
    31  func init() {
    32  	// Build a map that maps the names of the various information_schema tables
    33  	// to their CREATE TABLE AST.
    34  	for _, table := range informationSchemaTables {
    35  		parsed, err := parser.ParseOne(table)
    36  		if err != nil {
    37  			panic(errors.Wrap(err, "error initializing virtual table map"))
    38  		}
    39  
    40  		ct, ok := parsed.AST.(*tree.CreateTable)
    41  		if !ok {
    42  			panic(errors.New("virtual table schemas must be CREATE TABLE statements"))
    43  		}
    44  
    45  		ct.Table.SchemaName = tree.Name("information_schema")
    46  		ct.Table.ExplicitSchema = true
    47  
    48  		ct.Table.CatalogName = testDB
    49  		ct.Table.ExplicitCatalog = true
    50  
    51  		name := ct.Table
    52  		informationSchemaMap[name.ObjectName.String()] = ct
    53  	}
    54  }
    55  
    56  // Resolve returns true and the AST node describing the virtual table referenced.
    57  // TODO(justin): make this complete for all virtual tables.
    58  func resolveVTable(name *tree.TableName) (*tree.CreateTable, bool) {
    59  	switch name.SchemaName {
    60  	case "information_schema":
    61  		schema, ok := informationSchemaMap[name.ObjectName.String()]
    62  		return schema, ok
    63  	}
    64  
    65  	return nil, false
    66  }