yvbolt/db_sqlite.go

321 lines
7.6 KiB
Go

package main
import (
"database/sql"
"errors"
"fmt"
"path/filepath"
"unsafe"
_ "yvbolt/sqliteclidriver"
"github.com/ying32/govcl/vcl"
)
const (
sqliteTablesCaption = "Tables"
sqliteFilter = "SQLite database|*.db;*.db3;*.sqlite;*.sqlite3|All files|*.*"
)
type sqliteLoadedDatabase struct {
displayName string
path string
db *sql.DB
nav *vcl.TTreeNode
arena []*navData // keepalive
}
func (ld *sqliteLoadedDatabase) DisplayName() string {
return ld.displayName
}
func (ld *sqliteLoadedDatabase) RootElement() *vcl.TTreeNode {
return ld.nav
}
func (ld *sqliteLoadedDatabase) Keepalive(ndata *navData) {
ld.arena = append(ld.arena, ndata)
}
func (ld *sqliteLoadedDatabase) RenderForNav(f *TMainForm, ndata *navData) error {
if len(ndata.bucketPath) == 0 {
// Top-level
f.propertiesBox.SetText("Please select...")
return nil
} else if len(ndata.bucketPath) == 1 {
// Category (tables, ...)
f.propertiesBox.SetText("Please select...")
return nil
} else if len(ndata.bucketPath) == 2 && ndata.bucketPath[0] == sqliteTablesCaption {
// Render for specific table
tableName := ndata.bucketPath[1]
// Get some basic properties
r := ld.db.QueryRow(`SELECT sql FROM sqlite_schema WHERE name = ?;`, tableName)
var schemaStmt string
err := r.Scan(&schemaStmt)
if err != nil {
schemaStmt = fmt.Sprintf("* Failed to describe table %q: %s", tableName, err.Error())
}
// Display table properties
f.propertiesBox.SetText(fmt.Sprintf("Selected table %q\n\nSchema:\n\n%s", tableName, schemaStmt))
// Load column details
// Use SELECT form instead of common PRAGMA table_info so we can just get names
// We could possibly get this from the main data select, but this will
// work even when there are 0 results
columnNames, err := ld.sqliteGetColumnNamesForTable(tableName)
if err != nil {
return fmt.Errorf("Failed to load columns for table %q: %w", tableName)
}
populateColumns(columnNames, f.contentBox)
// Select count(*) so we know to display a warning if there are too many entries
// TODO
// Select * with small limit
datar, err := ld.db.Query(`SELECT * FROM "` + tableName + `" LIMIT 1000`) // WARNING can't prepare this parameter, but it comes from the DB (trusted)
if err != nil {
return fmt.Errorf("Failed to load data for table %q: %w", tableName, err)
}
defer datar.Close()
populateRows(datar, f.contentBox)
// We successfully populated the data grid
vcl_stringgrid_columnwidths(f.contentBox)
f.contentBox.SetEnabled(true)
return nil
} else {
// ??? unknown
return errors.New("?")
}
}
func (ld *sqliteLoadedDatabase) sqliteGetColumnNamesForTable(tableName string) ([]string, error) {
colr, err := ld.db.Query(`SELECT name FROM pragma_table_info( ? )`, tableName)
if err != nil {
return nil, fmt.Errorf("Query: %w", err)
}
defer colr.Close()
var ret []string
for colr.Next() {
var columnName string
err = colr.Scan(&columnName)
if err != nil {
return nil, fmt.Errorf("Scan: %w", colr.Err())
}
ret = append(ret, columnName)
}
if colr.Err() != nil {
return nil, colr.Err()
}
return ret, nil
}
func populateColumns(names []string, dest *vcl.TStringGrid) {
for _, columnName := range names {
col := dest.Columns().Add()
col.Title().SetCaption(columnName)
}
}
func populateRows(rr *sql.Rows, dest *vcl.TStringGrid) {
numColumns := int(dest.Columns().Count())
for rr.Next() {
fields := make([]interface{}, numColumns)
pfields := make([]interface{}, numColumns)
for i := 0; i < numColumns; i += 1 {
pfields[i] = &fields[i]
}
err := rr.Scan(pfields...)
if err != nil {
vcl.ShowMessageFmt("Failed to load data: %s", err.Error())
return
}
rpos := dest.RowCount()
dest.SetRowCount(rpos + 1)
for i := 0; i < len(fields); i += 1 {
dest.SetCells(int32(i), rpos, formatAny(fields[i]))
}
}
if rr.Err() != nil {
vcl.ShowMessageFmt("Failed to load data: %s", rr.Err().Error())
return
}
}
func (ld *sqliteLoadedDatabase) ExecQuery(query string, resultArea *vcl.TStringGrid) error {
rr, err := ld.db.Query(query)
if err != nil {
return err
}
defer rr.Close()
vcl_stringgrid_clear(resultArea)
columns, err := rr.Columns()
if err != nil {
return err
}
populateColumns(columns, resultArea)
populateRows(rr, resultArea)
vcl_stringgrid_columnwidths(resultArea)
resultArea.SetEnabled(true)
return nil
}
func (ld *sqliteLoadedDatabase) NavChildren(ndata *navData) ([]string, error) {
if len(ndata.bucketPath) == 0 {
// The top-level children are always:
return []string{sqliteTablesCaption}, nil
}
if len(ndata.bucketPath) == 1 && ndata.bucketPath[0] == sqliteTablesCaption {
rr, err := ld.db.Query(`SELECT name FROM sqlite_master WHERE type='table' ORDER BY name ASC;`)
if err != nil {
return nil, err
}
defer rr.Close()
var gather []string
for rr.Next() {
var tableName string
err = rr.Scan(&tableName)
if err != nil {
return nil, err
}
gather = append(gather, tableName)
}
if rr.Err() != nil {
return nil, rr.Err()
}
return gather, nil
}
if len(ndata.bucketPath) == 2 {
return nil, nil // Never any deeper children
}
return nil, fmt.Errorf("unknown nav path %#v", ndata.bucketPath)
}
func (ld *sqliteLoadedDatabase) NavContext(ndata *navData) (ret []contextAction, err error) {
if len(ndata.bucketPath) == 0 {
ret = append(ret, contextAction{"Compact database", ld.CompactDatabase})
ret = append(ret, contextAction{"Export backup...", ld.ExportBackup})
}
if len(ndata.bucketPath) == 2 {
ret = append(ret, contextAction{"Drop table", ld.DropTable})
}
return
}
func (ld *sqliteLoadedDatabase) CompactDatabase(sender vcl.IComponent, ndata *navData) error {
_, err := ld.db.Exec(`VACUUM;`)
return err
}
func (ld *sqliteLoadedDatabase) ExportBackup(sender vcl.IComponent, ndata *navData) error {
// Popup for output file
dlg := vcl.NewSaveDialog(sender)
dlg.SetTitle("Save backup as...")
dlg.SetFilter(sqliteFilter)
ret := dlg.Execute() // Fake blocking
if !ret {
return nil // cancelled
}
_, err := ld.db.Exec(`VACUUM INTO ?`, dlg.FileName())
return err
}
func (ld *sqliteLoadedDatabase) DropTable(sender vcl.IComponent, ndata *navData) error {
if len(ndata.bucketPath) != 2 {
return errors.New("Invalid selection")
}
//
tableName := ndata.bucketPath[1]
if !vcl_confirm_dialog(sender, "Drop table", fmt.Sprintf("Are you sure you want to drop the table %q?", tableName)) {
return nil // cancelled
}
_, err := ld.db.Exec(`DROP TABLE "` + tableName + `"`) // WARNING can't prepare this parameter, but it comes from the DB (trusted)
return err
}
func (ld *sqliteLoadedDatabase) Close() {
_ = ld.db.Close()
ld.arena = nil
}
var _ loadedDatabase = &sqliteLoadedDatabase{} // interface assertion
//
func (f *TMainForm) sqliteAddDatabaseFromFile(path string, cliDriver bool) {
driver := "sqlite3"
if cliDriver {
driver = "sqliteclidriver"
}
// TODO load in background thread to stop blocking the UI
db, err := sql.Open(driver, path)
if err != nil {
vcl.ShowMessage(fmt.Sprintf("Failed to load database '%s': %s", path, err.Error()))
return
}
ld := &sqliteLoadedDatabase{
path: path,
displayName: filepath.Base(path),
db: db,
}
ld.nav = f.Buckets.Items().Add(nil, ld.displayName)
ld.nav.SetImageIndex(imgDatabase)
ld.nav.SetSelectedIndex(imgDatabase)
ld.nav.SetHasChildren(true) // dynamically populate in OnNavExpanding
navData := &navData{
ld: ld,
childrenLoaded: false, // will be loaded dynamically
bucketPath: []string{}, // empty = root
}
ld.nav.SetData(unsafe.Pointer(navData))
f.dbs = append(f.dbs, ld)
f.Buckets.SetSelected(ld.nav) // Select new element
ld.Keepalive(navData)
}