SQLBuilder.py

from typing import Optional,Any,Literal
def object_item(target:object):
    for key in target.__dict__:
        value = getattr(target,key)
        if(key.find("__") == -1):
            yield (key,value)
def type_convert(var:Any):
    SQLType = {
        "str":"varchar",
        "int":"int",
        "float":"float",
        "bool":""
    }
    return SQLType[type(var).__name__]
def getClassName(cls):
    return cls.__class__.__name__
def generator_sql(obj):
    table = []
    if(not hasattr(obj,"__class__")):
        raise TypeError("not a class")
    table_name = getClassName(obj)
    for key,value in object_item(obj):
        col = []
        col.append(key)
        col.append(type_convert(value))
        table.append(" ".join(col))
    table_sql = "{}({})".format(table_name,",".join(table))
    return table_sql + ";"
def table_with_column(obj):
    table = getClassName(obj)
    col = []
    for key,_ in object_item(obj):
        col.append(key)
    return "{}({})".format(table,",".join(col))
def generator_params(obj:Any):
    expression = ["insert into"]
    params = []
    for _ in object_item(obj):
        params.append("?")
    params_str = ",".join(params)
    expression.append(table_with_column(obj))
    expression.append("values")
    expression.append("({})".format(params_str))
    return " ".join(expression)

def params_to_value(obj):
    params_str = generator_params(obj=obj)
    for _,value in object_item(obj):
        params_str = params_str.replace("?",str(value),1)
    return params_str+";"

def Where(WhereType:Literal["or","and"]="or",**kws):
    expression = ["where"]
    selector = []
    for key,value in kws.items():
        selector.append("{}={}".format(key,value))
    expression.append(f" {WhereType} ".join(selector))
    return " ".join(expression)+";"


def Select(obj,all=False):
    expression = ["select"]
    col = []
    table = getClassName(obj)
    value_map = {}
    if not all:
        for key,value in object_item(obj):
            col.append(key)
            value_map[key] = value
        expression.append("({})".format(",".join(col)))
    else:
        expression.append("*")
    expression.append("from")
    expression.append(table)
    return " ".join(expression)

if __name__ == "__main__":
    from pydantic.dataclasses import dataclass
    @dataclass
    class User:
        username:Optional[str] = ""
        age:Optional[int] = 0
        phone:Optional[str] = ""
    user = User(username="张三",age=33)
    print(generator_params(user))
    print(params_to_value(user))
    print(Where(some=12,rep="jim"))
    print(Select(user))