Question

我已经看到以下两个答案：

这两种解决方案都不适合我。我运行下面的代码，每次完成都没有任何错误，但根本没有修改mysql表Compounds，我已经验证输入文件的格式与格式完全匹配我的mysql表并且它被正确分隔而不是空。

import os, sys
import mysql.connector
from mysql.connector import errorcode
from mysql.connector.constants import ClientFlag

TABLE_NAME = "Compounds"
fullDataFile  = "data/compounds/parsed/fullData.csv"
cnx = mysql.connector.connect(user='kharland', passwd='password', db='mydb', client_flags=[ClientFlag.LOCAL_FILES])
cursor = cnx.cursor()
print "loading data file: %s/%s" % (os.getcwd(), fullDataFile)
try:
  cursor.execute = (
    "LOAD DATA LOCAL INFILE '%s/%s'"
    " REPLACE"
    " INTO TABLE `%s`"
    " FIELDS TERMINATED BY '^'"
    " LINES TERMINATED BY '\n'"
    " (PUBCHEM_COMPOUND_CID,"
    " PUBCHEM_COMPOUND_CANONICALIZED,"
    " PUBCHEM_CACTVS_COMPLEXITY,"
    " PUBCHEM_CACTVS_HBOND_ACCEPTOR,"
    " PUBCHEM_CACTVS_HBOND_DONOR,"
    " PUBCHEM_CACTVS_ROTATABLE_BOND,"
    " PUBCHEM_CACTVS_SUBSKEYS,"
    " PUBCHEM_IUPAC_INCHI,"
    " PUBCHEM_IUPAC_INCHIKEY,"
    " PUBCHEM_EXACT_MASS,"
    " PUBCHEM_MOLECULAR_FORMULA,"
    " PUBCHEM_MOLECULAR_WEIGHT,"
    " PUBCHEM_OPENEYE_CAN_SMILES,"
    " PUBCHEM_OPENEYE_ISO_SMILES,"
    " PUBCHEM_CACTVS_TPSA,"
    " PUBCHEM_MONOISOTOPIC_WEIGHT,"
    " PUBCHEM_TOTAL_CHARGE,"
    " PUBCHEM_HEAVY_ATOM_COUNT,"
    " PUBCHEM_ATOM_DEF_STEREO_COUNT,"
    " PUBCHEM_ATOM_UDEF_STEREO_COUNT,"  
    " PUBCHEM_BOND_DEF_STEREO_COUNT,"
    " PUBCHEM_BOND_UDEF_STEREO_COUNT,"
    " PUBCHEM_ISOTOPIC_ATOM_COUNT,"
    " PUBCHEM_COMPONENT_COUNT,"
    " PUBCHEM_CACTVS_TAUTO_COUNT);"  %
    (os.getcwd(), fullDataFile, TABLE_NAME))
  cnx.commit()
except mysql.connector.Error as e:
  sys.stderr.write("x Failed loading data: {}\n".format(e))

但是，如果我将此查询打印到终端然后在mysql中运行，那么它的工作正常。有没有理由mysql lib可能无法运行实际查询，或者我错过了一些函数调用？

Answer 1

MySQL不接受标识符的绑定占位符。在这种情况下，表的名称。这必须是SQL文本的一部分。您只能使用绑定占位符提供值。

你可以这样做：

SELECT t.id FROM mytable t WHERE t.foo = :val
                                         ^^^^

但这无效：

SELECT t.id FROM :mytable t WHERE t.foo = 'bar'
                 ^^^^^^^^

您可以执行sprintf类型操作作为前一步骤，以生成包含实际表名的SQL文本（字符串），然后将该SQL文本（字符串）提交给MySQL。

当你到达那个cursor.execute时，你需要SQL文本包含表名作为字符串的一部分。（也可能是文件的名称必须指定为文字，并且不能是占位符，但我不确定。我确定的是表名。）

作为测试，尝试硬编码表名“Compounds”并将文件名硬编码到SQL文本中......

cursor.execute = (
    "LOAD DATA LOCAL INFILE '/opt/data/compounds/parsed/fullData.csv'"
    " REPLACE"
    " INTO TABLE `Compounds`"

mysql / connector python查询在mysql中运行，但不在python中运行

1 个答案: