diff --git a/_example/vtable/main.go b/_example/vtable/main.go new file mode 100644 index 0000000..442069f --- /dev/null +++ b/_example/vtable/main.go @@ -0,0 +1,37 @@ +package main + +import ( + "database/sql" + "fmt" + "github.com/mattn/go-sqlite3" + "log" +) + +func main() { + sql.Register("sqlite3_with_extensions", &sqlite3.SQLiteDriver{ + ConnectHook: func(conn *sqlite3.SQLiteConn) error { + return conn.CreateModule("github", githubModule{}) + }, + }) + db, err := sql.Open("sqlite3_with_extensions", ":memory:") + if err != nil { + log.Fatal(err) + } + defer db.Close() + + _, err = db.Exec("create virtual table repo using github(id, full_name, description, html_url)") + if err != nil { + log.Fatal(err) + } + + rows, err := db.Query("select id, full_name, description, html_url from repo") + if err != nil { + log.Fatal(err) + } + defer rows.Close() + for rows.Next() { + var id, full_name, description, html_url string + rows.Scan(&id, &full_name, &description, &html_url) + fmt.Printf("%s: %s\n\t%s\n\t%s\n\n", id, full_name, description, html_url) + } +} diff --git a/_example/vtable/vtable.go b/_example/vtable/vtable.go new file mode 100644 index 0000000..cc0f308 --- /dev/null +++ b/_example/vtable/vtable.go @@ -0,0 +1,110 @@ +package main + +import ( + "encoding/json" + "fmt" + "github.com/mattn/go-sqlite3" + "io/ioutil" + "net/http" +) + +type GithubRepo struct { + ID int `json:"id"` + FullName string `json:"full_name"` + Description string `json:"description"` + HtmlURL string `json:"html_url"` +} + +type githubModule struct { +} + +func (m githubModule) Create(c *sqlite3.SQLiteConn, args []string) (sqlite3.VTab, error) { + err := c.DeclareVTab(fmt.Sprintf(` + CREATE TABLE %s ( + id INT, + full_name TEXT, + description TEXT, + html_url TEXT + )`, args[0])) + if err != nil { + return nil, err + } + return &ghRepoTable{}, nil +} + +func (m githubModule) Connect(c *sqlite3.SQLiteConn, args []string) (sqlite3.VTab, error) { + return m.Create(c, args) +} + +func (m githubModule) DestroyModule() {} + +type ghRepoTable struct { + repos []GithubRepo +} + +func (v *ghRepoTable) Open() (sqlite3.VTabCursor, error) { + resp, err := http.Get("https://api.github.com/repositories") + if err != nil { + return nil, err + } + defer resp.Body.Close() + + body, err := ioutil.ReadAll(resp.Body) + if err != nil { + return nil, err + } + + repos := make([]GithubRepo, 0) + if err := json.Unmarshal(body, &repos); err != nil { + return nil, err + } + return &ghRepoCursor{0, repos}, nil +} + +func (v *ghRepoTable) BestIndex(cst []sqlite3.InfoConstraint, ob []sqlite3.InfoOrderBy) (*sqlite3.IndexResult, error) { + return &sqlite3.IndexResult{}, nil +} + +func (v *ghRepoTable) Disconnect() error { return nil } +func (v *ghRepoTable) Destroy() error { return nil } + +type ghRepoCursor struct { + index int + repos []GithubRepo +} + +func (vc *ghRepoCursor) Column(c *sqlite3.Context, col int) error { + switch col { + case 0: + c.ResultInt(vc.repos[vc.index].ID) + case 1: + c.ResultText(vc.repos[vc.index].FullName) + case 2: + c.ResultText(vc.repos[vc.index].Description) + case 3: + c.ResultText(vc.repos[vc.index].HtmlURL) + } + return nil +} + +func (vc *ghRepoCursor) Filter(idxNum int, idxStr string, vals []interface{}) error { + vc.index = 0 + return nil +} + +func (vc *ghRepoCursor) Next() error { + vc.index++ + return nil +} + +func (vc *ghRepoCursor) EOF() bool { + return vc.index >= len(vc.repos) +} + +func (vc *ghRepoCursor) Rowid() (int64, error) { + return int64(vc.index), nil +} + +func (vc *ghRepoCursor) Close() error { + return nil +}