export class SqlValidator {
/**
* 验证SQL语句是否为SELECT查询
*/
static isSelectQuery(sql: string): boolean {
const trimmedSql = sql.trim().toLowerCase();
return trimmedSql.startsWith('select ');
}
/**
* 验证SQL语句是否为CREATE TABLE语句
*/
static isCreateTableQuery(sql: string): boolean {
const trimmedSql = sql.trim().toLowerCase();
return trimmedSql.startsWith('create table ');
}
/**
* 验证SQL语句是否为INSERT语句
*/
static isInsertQuery(sql: string): boolean {
const trimmedSql = sql.trim().toLowerCase();
return trimmedSql.startsWith('insert ');
}
/**
* 验证SQL语句是否为UPDATE语句
*/
static isUpdateQuery(sql: string): boolean {
const trimmedSql = sql.trim().toLowerCase();
return trimmedSql.startsWith('update ');
}
/**
* 验证SQL语句是否为DELETE语句
*/
static isDeleteQuery(sql: string): boolean {
const trimmedSql = sql.trim().toLowerCase();
return trimmedSql.startsWith('delete ');
}
/**
* 验证SQL语句是否为DDL语句（CREATE, ALTER, DROP等）
*/
static isDdlQuery(sql: string): boolean {
const trimmedSql = sql.trim().toLowerCase();
return (
trimmedSql.startsWith('create ') ||
trimmedSql.startsWith('alter ') ||
trimmedSql.startsWith('drop ') ||
trimmedSql.startsWith('truncate ')
);
}
/**
* 检查SQL语句是否包含危险操作
*/
static hasDangerousOperations(sql: string): boolean {
const dangerousKeywords = [
'drop database',
'drop table',
'truncate table',
'delete from',
'update ',
'alter table',
'create table',
'create database',
];
const lowerSql = sql.toLowerCase();
return dangerousKeywords.some(keyword => lowerSql.includes(keyword));
}
/**
* 获取SQL语句的类型
*/
static getSqlType(sql: string): 'SELECT' | 'INSERT' | 'UPDATE' | 'DELETE' | 'CREATE' | 'ALTER' | 'DROP' | 'OTHER' {
const trimmedSql = sql.trim().toLowerCase();
if (trimmedSql.startsWith('select ')) return 'SELECT';
if (trimmedSql.startsWith('insert ')) return 'INSERT';
if (trimmedSql.startsWith('update ')) return 'UPDATE';
if (trimmedSql.startsWith('delete ')) return 'DELETE';
if (trimmedSql.startsWith('create ')) return 'CREATE';
if (trimmedSql.startsWith('alter ')) return 'ALTER';
if (trimmedSql.startsWith('drop ')) return 'DROP';
return 'OTHER';
}
/**
* 验证SQL语句的基本语法
*/
static validateBasicSyntax(sql: string): { isValid: boolean; error?: string } {
const trimmedSql = sql.trim();
if (!trimmedSql) {
return { isValid: false, error: 'SQL statement cannot be empty' };
}
if (!trimmedSql.endsWith(';')) {
return { isValid: false, error: 'SQL statement must end with semicolon' };
}
// 检查是否包含基本的SQL关键字
const sqlKeywords = ['select', 'insert', 'update', 'delete', 'create', 'alter', 'drop', 'from', 'where', 'into', 'values', 'set'];
const hasKeyword = sqlKeywords.some(keyword =>
trimmedSql.toLowerCase().includes(keyword)
);
if (!hasKeyword) {
return { isValid: false, error: 'SQL statement must contain valid SQL keywords' };
}
return { isValid: true };
}
}