OleDb SQL 查询中的两个内部联接

Question

我正在尝试使用 OleDbCommand 对 Access 数据库 (.accdb) 进行 SQL 查询。

虽然此命令工作正常（在 OleDbCommand.ExecuteReader() 中）：

string command =
   "SELECT cred.* " +
   "FROM TB_CREDENTIALS cred " +
   "INNER JOIN TB_REL_USERS_CREDENTIALS rel ON cred.CRED_ID = rel.REL_USR_CRED_CRED_ID ";

另一个没有，我不明白为什么（我看到的所有示例都使用完全相同的语法）：

string command =
   "SELECT cred.* " +
   "FROM TB_CREDENTIALS cred " +
   "INNER JOIN TB_REL_USERS_CREDENTIALS rel ON cred.CRED_ID = rel.REL_USR_CRED_CRED_ID " +
   "INNER JOIN TB_USERS usr ON usr.USR_ID = rel.REL_USR_CRED_USER_ID ";

给出的异常如下System.Data.OleDb.OleDbException:

Syntax error (missing operator) in query expression 'cred.CRED_ID = rel.REL_USR_CRED_CRED_ID INNER JOIN TB_USERS usr ON usr.USR_ID = rel.REL_USR_CRED_USER_I' (message is cut here)

版本和详细信息：

数据库是在 Access 2010

.accdb

连接是在 C# 中创建的 System.Data.OleDb.OleDbConnection
连接提供商是"Microsoft.ACE.OLEDB.12.0"

(这似乎是一个无用的查询，但我当然会添加一个WHERE usr.SOME_FIELD = some_condition)

Answer 1

"For multi-table joins, you have to nest the extra joins in brackets:"

SQL multiple join statement

OleDb SQL 查询中的两个内部联接

Two Inner Joins in OleDb SQL query

c#

sql

oledb

oledbcommand

ms-access-2010