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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, err := s.QueryBySQL(ctx, dbName, query, limit)
if err != nil {
return nil, err
}
// 转换为map格式以保持兼容性
var mapResults []map[string]interface{}
if len(results) > 0 {
columns := results[0]
for _, row := range results[1:] {
rowMap := make(map[string]interface{})
for i, col := range columns {
if i < len(row) {
rowMap[col] = row[i]
}
}
mapResults = append(mapResults, rowMap)
}
}
return mapResults, nil
}
func (s *DMDBService) QueryBySQL(ctx context.Context, dbName string, sql string, limit int) ([][]string, error) {
// 添加LIMIT子句如果SQL中没有
if !strings.Contains(strings.ToUpper(sql), "LIMIT") && !strings.Contains(strings.ToUpper(sql), "ROWNUM") {
sql = fmt.Sprintf("SELECT * FROM (%s) WHERE ROWNUM <= %d", sql, limit)
}
rows, err := s.db.QueryxContext(ctx, sql)
if err != nil {
return nil, err
}
defer rows.Close()
// 获取列名
columns, err := rows.Columns()
if err != nil {
return nil, err
}
var results [][]string
// 添加列名作为第一行
results = append(results, columns)
// 处理数据行
for rows.Next() {
// 创建动态接收器
values := make([]interface{}, len(columns))
for i := range values {
var v interface{}
values[i] = &v
}
if err := rows.Scan(values...); err != nil {
return nil, err
}
// 转换为字符串数组
row := make([]string, len(columns))
for i, val := range values {
if val == nil {
row[i] = "NULL"
} else {
row[i] = fmt.Sprintf("%v", *val.(*interface{}))
}
}
results = append(results, row)
}
return results, 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
}
// ColumnInfo 表字段信息(用于表结构查询)
type ColumnInfo struct {
ColumnName string `db:"COLUMN_NAME"`
DataType string `db:"DATA_TYPE"`
DataLength *int `db:"DATA_LENGTH"`
Nullable string `db:"NULLABLE"`
DataDefault *string `db:"DATA_DEFAULT"`
ColumnComment string `db:"COMMENTS"`
}
// TableStructure 查询表结构(字段名、类型、长度、可空、默认值等)
func (s *DMDBService) TableStructure(ctx context.Context, dbName, tableName string) ([]ColumnInfo, error) {
// 达梦 ALL_TAB_COLUMNS / USER_TAB_COLUMNS;部分版本有注释在 ALL_COL_COMMENTS
query := `SELECT c.COLUMN_NAME, c.DATA_TYPE, c.DATA_LENGTH, c.NULLABLE, c.DATA_DEFAULT, com.COMMENTS
FROM ALL_TAB_COLUMNS c
LEFT JOIN ALL_COL_COMMENTS com ON c.OWNER = com.OWNER AND c.TABLE_NAME = com.TABLE_NAME AND c.COLUMN_NAME = com.COLUMN_NAME
WHERE c.OWNER = ? AND c.TABLE_NAME = ?
ORDER BY c.COLUMN_ID`
rows, err := s.db.QueryxContext(ctx, query, strings.ToUpper(dbName), strings.ToUpper(tableName))
if err != nil {
return nil, err
}
defer rows.Close()
var list []ColumnInfo
for rows.Next() {
var c ColumnInfo
if err := rows.StructScan(&c); err != nil {
return nil, err
}
list = append(list, c)
}
return list, nil
}
// ExecSQL 执行非查询 SQL(INSERT/UPDATE/DELETE),返回影响行数;args 为参数化占位符对应的值
func (s *DMDBService) ExecSQL(ctx context.Context, sql string, args ...interface{}) (int64, error) {
var err error
var affected int64
if len(args) > 0 {
res, e := s.db.ExecContext(ctx, sql, args...)
err = e
if e == nil {
affected, _ = res.RowsAffected()
}
} else {
res, e := s.db.ExecContext(ctx, sql)
err = e
if e == nil {
affected, _ = res.RowsAffected()
}
}
if err != nil {
return 0, err
}
return affected, nil
}
// CreateTable 创建表(columnDefs 如 "id INT PRIMARY KEY, name VARCHAR(100)")
func (s *DMDBService) CreateTable(ctx context.Context, dbName, tableName, columnDefs string) error {
query := fmt.Sprintf("CREATE TABLE %s.%s (%s)", dbName, tableName, columnDefs)
_, err := s.db.ExecContext(ctx, query)
return err
}
// DropTable 删除表
func (s *DMDBService) DropTable(ctx context.Context, dbName, tableName string) error {
query := fmt.Sprintf("DROP TABLE %s.%s", dbName, tableName)
_, 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, err := s.QueryBySQL(ctx, dbName, query, 1000) // 默认限制1000条表名
if err != nil {
return nil, err
}
// 转换为map格式以保持兼容性
var mapResults []map[string]interface{}
if len(results) > 0 {
columns := results[0]
for _, row := range results[1:] {
rowMap := make(map[string]interface{})
for i, col := range columns {
if i < len(row) {
rowMap[col] = row[i]
}
}
mapResults = append(mapResults, rowMap)
}
}
return mapResults, nil
}