connector.go•8.44 kB
package sqlite
import (
"context"
"database/sql"
"fmt"
"strings"
"github.com/centralmind/gateway/castx"
"github.com/centralmind/gateway/connectors"
"github.com/centralmind/gateway/model"
_ "github.com/glebarez/go-sqlite"
"github.com/jmoiron/sqlx"
"golang.org/x/xerrors"
)
func init() {
connectors.Register[Config](func(cfg Config) (connectors.Connector, error) {
connStr := cfg.ConnectionString()
// Remove sqlite:// prefix if present
connStr = strings.TrimPrefix(connStr, "sqlite://")
// Add read-only mode if specified
if cfg.ReadOnly {
if strings.Contains(connStr, "?") {
connStr += "&mode=ro"
} else {
connStr += "?mode=ro"
}
}
db, err := sqlx.Connect("sqlite", connStr)
if err != nil {
return nil, fmt.Errorf("unable to connect to sqlite: %v", err)
}
return &Connector{
config: cfg,
db: db,
base: &connectors.BaseConnector{DB: db},
}, nil
})
}
// Connector implements the connectors.Connector interface for SQLite
type Connector struct {
config Config
db *sqlx.DB
base *connectors.BaseConnector
}
func (c Connector) Config() connectors.Config {
return c.config
}
// GuessColumnType implements TypeGuesser interface for SQLite
func (c *Connector) GuessColumnType(sqlType string) model.ColumnType {
upperType := strings.ToUpper(sqlType)
// String types
switch upperType {
case "TEXT", "VARCHAR", "CHAR", "CLOB":
return model.TypeString
}
// Numeric types
switch upperType {
case "REAL", "FLOAT", "DOUBLE":
return model.TypeNumber
}
// Integer types
switch upperType {
case "INTEGER", "INT", "BIGINT", "SMALLINT", "TINYINT":
return model.TypeInteger
}
// Boolean type
switch upperType {
case "BOOLEAN":
return model.TypeBoolean
}
// Date/Time types
switch upperType {
case "DATETIME", "DATE", "TIME":
return model.TypeDatetime
}
// Default to string for unknown types
return model.TypeString
}
func (c Connector) Sample(ctx context.Context, table model.Table) ([]map[string]any, error) {
tx, err := c.db.BeginTxx(ctx, &sql.TxOptions{
ReadOnly: true,
})
if err != nil {
return nil, xerrors.Errorf("BeginTx failed with error: %w", err)
}
defer tx.Commit()
rows, err := tx.NamedQuery(fmt.Sprintf("SELECT * FROM %s LIMIT 5", table.Name), map[string]any{})
if err != nil {
return nil, xerrors.Errorf("unable to query db: %w", err)
}
defer rows.Close()
res := make([]map[string]any, 0, 5)
for rows.Next() {
row := map[string]any{}
if err := rows.MapScan(row); err != nil {
return nil, xerrors.Errorf("unable to scan row: %w", err)
}
res = append(res, row)
}
return res, nil
}
func (c Connector) Discovery(ctx context.Context, tablesList []string) ([]model.Table, error) {
// Create a map for quick lookups if tablesList is provided
tableSet := make(map[string]bool)
if len(tablesList) > 0 {
for _, table := range tablesList {
tableSet[table] = true
}
}
var query string
var args []interface{}
if len(tablesList) > 0 {
// If specific tables are requested, build a query with IN clause
placeholders := make([]string, len(tablesList))
args = make([]interface{}, len(tablesList))
for i, table := range tablesList {
placeholders[i] = "?"
args[i] = table
}
query = fmt.Sprintf(`
SELECT name
FROM sqlite_master
WHERE type='table'
AND name NOT LIKE 'sqlite_%%'
AND name IN (%s)`, strings.Join(placeholders, ","))
} else {
// Otherwise, query all tables
query = `
SELECT name
FROM sqlite_master
WHERE type='table'
AND name NOT LIKE 'sqlite_%'`
}
// Query tables in the database
rows, err := c.db.QueryContext(ctx, query, args...)
if err != nil {
return nil, xerrors.Errorf("unable to query tables: %w", err)
}
defer rows.Close()
var tables []model.Table
for rows.Next() {
var tableName string
if err := rows.Scan(&tableName); err != nil {
return nil, xerrors.Errorf("unable to scan table name: %w", err)
}
columns, err := c.LoadsColumns(ctx, tableName)
if err != nil {
return nil, xerrors.Errorf("unable to load columns for table %s: %w", tableName, err)
}
// Get the total row count for this table
var rowCount int
countQuery := fmt.Sprintf("SELECT COUNT(*) FROM %s", tableName)
err = c.db.Get(&rowCount, countQuery)
if err != nil {
return nil, xerrors.Errorf("unable to get row count for table %s: %w", tableName, err)
}
table := model.Table{
Name: tableName,
Columns: columns,
RowCount: rowCount,
}
tables = append(tables, table)
}
return tables, nil
}
func (c Connector) Ping(ctx context.Context) error {
rows, err := c.db.QueryContext(ctx, "SELECT 1")
if err != nil {
return xerrors.Errorf("unable to ping db: %w", err)
}
defer rows.Close()
for rows.Next() {
var res int
if err := rows.Scan(&res); err != nil {
return xerrors.Errorf("unable to scan ping result: %w", err)
}
}
if rows.Err() != nil {
return xerrors.Errorf("rows fetcher failed: %w", err)
}
return nil
}
func (c Connector) Query(ctx context.Context, endpoint model.Endpoint, params map[string]any) ([]map[string]any, error) {
processed, err := castx.ParamsE(endpoint, params)
if err != nil {
return nil, xerrors.Errorf("unable to process params: %w", err)
}
// If there are no parameters to process, use direct query execution
if len(processed) == 0 {
rows, err := c.db.QueryContext(ctx, endpoint.Query)
if err != nil {
return nil, xerrors.Errorf("unable to execute query: %w", err)
}
defer rows.Close()
// Get column names
columns, err := rows.Columns()
if err != nil {
return nil, xerrors.Errorf("unable to get columns: %w", err)
}
// Create a slice of interface{} to store the values
values := make([]interface{}, len(columns))
valuePtrs := make([]interface{}, len(columns))
for i := range values {
valuePtrs[i] = &values[i]
}
var result []map[string]any
for rows.Next() {
if err := rows.Scan(valuePtrs...); err != nil {
return nil, xerrors.Errorf("unable to scan row: %w", err)
}
row := make(map[string]any)
for i, col := range columns {
row[col] = values[i]
}
result = append(result, row)
}
return result, nil
}
// For parameterized queries, use transaction-based approach
tx, err := c.db.BeginTxx(ctx, &sql.TxOptions{
ReadOnly: c.Config().Readonly(),
})
if err != nil {
return nil, xerrors.Errorf("BeginTx failed with error: %w", err)
}
defer tx.Commit()
rows, err := tx.NamedQuery(endpoint.Query, processed)
if err != nil {
return nil, xerrors.Errorf("unable to execute query: %w", err)
}
defer rows.Close()
res := make([]map[string]any, 0)
for rows.Next() {
row := map[string]any{}
if err := rows.MapScan(row); err != nil {
return nil, xerrors.Errorf("unable to scan row: %w", err)
}
res = append(res, row)
}
return res, nil
}
func (c Connector) LoadsColumns(ctx context.Context, tableName string) ([]model.ColumnSchema, error) {
// Query column information from SQLite
rows, err := c.db.Query(`
SELECT name, type, pk
FROM pragma_table_info(?)
ORDER BY cid`, tableName)
if err != nil {
return nil, xerrors.Errorf("unable to query columns: %w", err)
}
defer rows.Close()
var columns []model.ColumnSchema
for rows.Next() {
var name, sqlType string
var pk int
if err := rows.Scan(&name, &sqlType, &pk); err != nil {
return nil, xerrors.Errorf("unable to scan column info: %w", err)
}
// Extract base type without length/precision
baseType := strings.Split(sqlType, "(")[0]
baseType = strings.TrimSpace(baseType)
column := model.ColumnSchema{
Name: name,
Type: c.GuessColumnType(baseType),
PrimaryKey: pk == 1,
}
columns = append(columns, column)
}
return columns, nil
}
func (c *Connector) InferQuery(ctx context.Context, query string) ([]model.ColumnSchema, error) {
// Create a temporary view to analyze the query
viewName := "temp_view_" + fmt.Sprintf("%d", ctx.Value("request_id"))
createViewSQL := fmt.Sprintf("CREATE TEMPORARY VIEW %s AS %s", viewName, query)
_, err := c.db.Exec(createViewSQL)
if err != nil {
return nil, xerrors.Errorf("unable to create temporary view: %w", err)
}
defer c.db.Exec("DROP VIEW " + viewName)
// Get column information from the temporary view
columns, err := c.LoadsColumns(ctx, viewName)
if err != nil {
return nil, xerrors.Errorf("unable to load columns from temporary view: %w", err)
}
return columns, nil
}