SQL中联表的运用

当出现要大量数据去查询时，不要一个个去SQL查询，应该要批量的去查询。

def batch_cavity_query(self, fuseids):

"""批量查询cavity信息"""

if not fuseids:

return {}

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# 创建临时表批量查询
try:
    # 创建临时表
    self.cursor.execute("CREATE TABLE #TempFuseIDs (fuseid VARCHAR(100))")
    # 批量插入数据
    self.cursor.executemany("INSERT INTO #TempFuseIDs VALUES (%s)", [(fid,) for fid in fuseids])

    query = """
    SELECT 
        DA.qrc_fuseid,
        C.Barcode AS QRcode,
        L.qrc_fuseid AS LensData_FuseID,
        C.Cavity
    FROM #TempFuseIDs temp
    LEFT JOIN A DA
        ON temp.fuseid = DA.qrc_fuseid
    LEFT JOIN B L
        ON DA.qrc_QRcode = L.qrc_QRcode
    LEFT JOIN C C
        ON L.qrc_fuseid = C.Barcode
    """
    self.cursor.execute(query)
    results = self.cursor.fetchall()

    # 构建映射字典
    cavity_map = {}
    for row in results:
        fuseid = row[0]
        cavity_map[fuseid] = (row[1], row[2], row[3])

    return cavity_map
finally:
    self.cursor.execute("DROP TABLE #TempFuseIDs")

python 复制代码

def batch_query_sn(self, fuseids):
    """批量查询SN相关信息"""
    if not fuseids:
        return {}

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try:
    # 创建临时表
    self.cursor.execute("CREATE TABLE #TempFuseIDs (fuseid VARCHAR(100))")
    self.cursor.executemany("INSERT INTO #TempFuseIDs VALUES (%s)", [(fid,) for fid in fuseids])

    query = """
    SELECT 
        temp.fuseid,
        eqp_name,
        station_code,
        TRY_CAST(testres_main_test_recordposition3_ut_z AS FLOAT) - 
        TRY_CAST(testres_main_test_recordposition2_ut_z AS FLOAT) AS offset,
        time
    FROM #TempFuseIDs temp
    LEFT JOIN D  AA
        ON AA.sensor_id = temp.fuseid
    """
    self.cursor.execute(query)
    results = self.cursor.fetchall()

    sn_map = {}
    for row in results:
        fuseid = row[0]
        sn_map[fuseid] = (row[1], row[2], float(row[3]) if row[3] else 0, row[4])

    return sn_map
finally:
    self.cursor.execute("DROP TABLE #TempFuseIDs")

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