1136, "Column count doesn't match value count at row 1"问题解决

我参考：python爬取拉勾网招聘信息并利用pandas做简单数据分析

写了一个python3.6 版本的脚本，部分内容如下：

sql_insert = '''INSERT INTO positions(companyId, businessZones, companyFullName, positionName,
                 education, city, financeStage, salary, workYear, companySize, industryField, positionAdvantage, 
                 companyLabelList)
                 VALUES({0}, {1}, {2}, {3}, {4}, {5}, {6}, {7}, {8}, {9}, {10}, {11}, {12})'''.\
                    format(companyId, businessZones, companyFullName, positionName, education, city, financeStage,
                           salary, workYear, companySize, industryField, positionAdvantage, companyLabelList)
cur.execute(sql_insert)

返回错误：

pymysql.err.InternalError: (1136, "Column count doesn't match value count at row 1")

但是将脚本改成：

sql_insert = '''INSERT INTO positions(companyId, businessZones, companyFullName, positionName,
                 education, city, financeStage, salary, workYear, companySize, industryField, positionAdvantage, 
                 companyLabelList)
                 VALUES({0}, '{1}', '{2}', '{3}', '{4}', '{5}', '{6}', '{7}', '{8}', '{9}', '{10}', '{11}', '{12}')'''.\
                    format(companyId, businessZones, companyFullName, positionName, education, city, financeStage,
                           salary, workYear, companySize, industryField, positionAdvantage, companyLabelList)
                cur.execute(sql_insert)
                    db.commit()

就可以插入成功。

为什么？

format()中的值本身就带有INT或者VARCHAR的特征。为什么还要给VALUES中的值加上“”？

再将脚本改成：

sql_insert = '''INSERT INTO positions(companyId, businessZones, companyFullName, positionName,
                 education, city, financeStage, salary, workYear, companySize, industryField, positionAdvantage, 
                 companyLabelList)
                 VALUES({0}, {1}, {2}, {3}, {4}, {5}, {6}, {7}, {8}, {9}, {10}, {11}, {12})'''.\
                    format(1,'2','3','4','5','6','7','8','9','10','11','12','13')

也可以运行成功，说明format（）中直接引用的变量值并不是string。

但是：

难道这是一种规定的语法吗？

在sql语句中的格式化引用中如果引用对象是字符串，则必须携程‘{}’？