connector.go•8.87 kB
package mysql
import (
"context"
"database/sql"
_ "embed"
"fmt"
"strings"
"github.com/centralmind/gateway/connectors"
"github.com/centralmind/gateway/castx"
"github.com/centralmind/gateway/model"
"github.com/go-sql-driver/mysql"
"github.com/jmoiron/sqlx"
"golang.org/x/xerrors"
"gopkg.in/yaml.v3"
)
//go:embed readme.md
var docString string
func init() {
connectors.Register(func(cfg Config) (connectors.Connector, error) {
dsn, err := cfg.MakeDSN()
if err != nil {
return nil, xerrors.Errorf("unable to prepare mysql config: %w", err)
}
db, err := sqlx.Open("mysql", dsn)
if err != nil {
return nil, xerrors.Errorf("unable to open mysql db: %w", err)
}
return &Connector{
config: cfg,
db: db,
base: &connectors.BaseConnector{DB: db},
}, nil
})
}
type Config struct {
Host string
Database string
User string
Password string
Port int
TLSConfig string
ConnString string `yaml:"conn_string"`
IsReadonly bool `yaml:"is_readonly"`
}
func (c Config) Readonly() bool {
return c.IsReadonly
}
// UnmarshalYAML implements the yaml.Unmarshaler interface to allow for both
// direct connection string or full configuration objects in YAML
func (c *Config) UnmarshalYAML(value *yaml.Node) error {
// Try to unmarshal as a string (connection string)
var connString string
if err := value.Decode(&connString); err == nil && len(connString) > 0 {
c.ConnString = connString
return nil
}
// If that didn't work, try to unmarshal as a full config object
type configAlias Config // Use alias to avoid infinite recursion
var alias configAlias
if err := value.Decode(&alias); err != nil {
return err
}
*c = Config(alias)
return nil
}
func (c Config) ExtraPrompt() []string {
return []string{}
}
func (c Config) MakeDSN() (string, error) {
// If connection string is provided, use it directly
if c.ConnString != "" {
return c.ConnString, nil
}
// Otherwise, build the DSN from individual fields
cfg := mysql.Config{
User: c.User,
Passwd: c.Password,
Net: "tcp",
Addr: fmt.Sprintf("%s:%d", c.Host, c.Port),
DBName: c.Database,
AllowNativePasswords: true,
ParseTime: true,
TLSConfig: c.TLSConfig,
}
return cfg.FormatDSN(), nil
}
func (c Config) Type() string {
return "mysql"
}
func (c Config) Doc() string {
return docString
}
type Connector struct {
config Config
db *sqlx.DB
base *connectors.BaseConnector
}
func (c Connector) Config() connectors.Config {
return c.config
}
func (c Connector) Sample(ctx context.Context, table model.Table) ([]map[string]any, error) {
tx, err := c.base.DB.BeginTxx(ctx, &sql.TxOptions{
ReadOnly: c.Config().Readonly(),
})
if err != nil {
return nil, xerrors.Errorf("BeginTx failed with error: %w", err)
}
rows, err := tx.QueryxContext(ctx, fmt.Sprintf("SELECT * FROM %s LIMIT 5", table.Name))
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 := make(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) {
tx, err := c.base.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()
// 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, only query those
placeholders := make([]string, len(tablesList))
args = make([]interface{}, len(tablesList))
for i, table := range tablesList {
placeholders[i] = "?"
args[i] = table
}
query = fmt.Sprintf("SHOW TABLES WHERE Tables_in_%s IN (%s)",
c.config.Database, strings.Join(placeholders, ","))
} else {
// Otherwise, query all tables
query = "SHOW TABLES"
}
rows, err := tx.QueryContext(ctx, query, args...)
if err != nil {
return nil, err
}
defer rows.Close()
var tables []model.Table
for rows.Next() {
var tableName string
if err := rows.Scan(&tableName); err != nil {
return nil, err
}
// Skip tables not in the list if a list was provided
if len(tablesList) > 0 && !tableSet[tableName] {
continue
}
columns, err := c.LoadsColumns(ctx, tableName)
if err != nil {
return nil, 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 {
return c.db.PingContext(ctx)
}
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)
}
tx, err := c.base.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 query db: %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, castx.Process(row))
}
return res, nil
}
func (c Connector) LoadsColumns(ctx context.Context, tableName string) ([]model.ColumnSchema, error) {
tx, err := c.base.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.QueryContext(
ctx,
`SELECT
COLUMN_NAME,
DATA_TYPE,
COLUMN_KEY = 'PRI' as is_primary_key
FROM information_schema.columns
WHERE table_name = ?
AND table_schema = ?`,
tableName, c.config.Database,
)
if err != nil {
return nil, err
}
defer rows.Close()
var columns []model.ColumnSchema
for rows.Next() {
var name, dataType string
var isPrimaryKey bool
if err := rows.Scan(&name, &dataType, &isPrimaryKey); err != nil {
return nil, err
}
columns = append(columns, model.ColumnSchema{
Name: name,
Type: c.GuessColumnType(dataType),
PrimaryKey: isPrimaryKey,
})
}
return columns, nil
}
// GuessColumnType implements TypeGuesser interface for MySQL
func (c *Connector) GuessColumnType(sqlType string) model.ColumnType {
upperType := strings.ToUpper(sqlType)
// Set type (mapped to array)
if strings.Contains(upperType, "SET") {
return model.TypeArray
}
// Object types
switch upperType {
case "JSON":
return model.TypeObject
}
// String types
switch upperType {
case "VARCHAR", "CHAR", "TEXT", "TINYTEXT", "MEDIUMTEXT", "LONGTEXT", "ENUM":
return model.TypeString
}
// Numeric types
switch upperType {
case "DECIMAL", "NUMERIC", "FLOAT", "DOUBLE":
return model.TypeNumber
}
// Integer types (except TINYINT(1) which is boolean)
switch upperType {
case "INT", "INTEGER", "BIGINT", "MEDIUMINT", "SMALLINT":
return model.TypeInteger
}
// Special case for TINYINT(1) which MySQL uses for boolean
if strings.Contains(upperType, "TINYINT(1)") {
return model.TypeBoolean
}
// Regular TINYINT is treated as integer
if strings.Contains(upperType, "TINYINT") {
return model.TypeInteger
}
// Boolean type
switch upperType {
case "BOOLEAN", "BOOL":
return model.TypeBoolean
}
// Date/Time types
switch upperType {
case "DATE", "TIME", "DATETIME", "TIMESTAMP", "YEAR":
return model.TypeDatetime
}
// Default to string for unknown types
return model.TypeString
}
// InferResultColumns returns column information for the given query
func (c *Connector) InferResultColumns(ctx context.Context, query string) ([]model.ColumnSchema, error) {
return c.base.InferResultColumns(ctx, query, c)
}
// InferQuery implements the Connector interface
func (c *Connector) InferQuery(ctx context.Context, query string) ([]model.ColumnSchema, error) {
return c.base.InferResultColumns(ctx, query, c)
}