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package vService
import (
"context"
_ "dm" // 达梦数据库驱动
"fmt"
"github.com/jmoiron/sqlx"
"log"
"strings"
)
// DMDBService 数据库服务实现
type DMDBService struct {
db *sqlx.DB
}
func NewDMDBService(dsn string) (*DMDBService, error) {
db, err := sqlx.Connect("dm", dsn)
if err != nil {
return nil, err
}
return &DMDBService{db: db}, nil
}
func (s *DMDBService) Close() error {
return s.db.Close()
}
func (s *DMDBService) FetchData(ctx context.Context, dbName, tableName string, limit int) ([]map[string]interface{}, error) {
query := fmt.Sprintf("SELECT * FROM %s.%s WHERE ROWNUM <= %d", dbName, tableName, limit)
results, i, err2 := s.queryBySQL(ctx, query)
if err2 != nil {
return i, err2
}
return results, nil
}
func (s *DMDBService) queryBySQL(ctx context.Context, query string) ([]map[string]interface{}, []map[string]interface{}, error) {
rows, err := s.db.QueryxContext(ctx, query)
if err != nil {
return nil, nil, err
}
defer rows.Close()
var results []map[string]interface{}
for rows.Next() {
row := make(map[string]interface{})
if err := rows.MapScan(row); err != nil {
return nil, nil, err
}
results = append(results, row)
}
return results, nil, nil
}
func (s *DMDBService) AddColumn(ctx context.Context, dbName, tableName, columnName, columnType string) error {
query := fmt.Sprintf("ALTER TABLE %s.%s ADD %s %s", dbName, tableName, columnName, columnType)
if _, err := s.db.ExecContext(ctx, query); err != nil {
return err
}
return nil
}
func (s *DMDBService) AddComment(ctx context.Context, dbName, tableName, columnName, comment string) error {
if comment != "" {
commentQuery := fmt.Sprintf("COMMENT ON COLUMN %s.%s.%s IS '%s'",
dbName, tableName, columnName, strings.ReplaceAll(comment, "'", "''"))
if _, err := s.db.ExecContext(ctx, commentQuery); err != nil {
return err
}
}
return nil
}
func (s *DMDBService) DropColumn(ctx context.Context, dbName, tableName, columnName string) error {
query := fmt.Sprintf("ALTER TABLE %s.%s DROP COLUMN %s", dbName, tableName, columnName)
_, err := s.db.ExecContext(ctx, query)
return err
}
func (s *DMDBService) AllTable(ctx context.Context, dbName string) (interface{}, error) {
query := fmt.Sprintf("SELECT TABLE_NAME FROM ALL_TABLES WHERE OWNER = '%s'", dbName)
rows, err := s.db.QueryxContext(ctx, query)
if err != nil {
return nil, err
}
defer func(rows *sqlx.Rows) {
err := rows.Close()
if err != nil {
log.Fatalf("发生异常: %v", err)
}
}(rows)
results, i, err := s.queryBySQL(ctx, query)
if err != nil {
return i, err
}
return results, nil
}