add double/float supporting for query class of db module

Author: zhengshuxin

lib_acl_cpp/include/acl_cpp/db/query.hpp

@@ -61,17 +61,19 @@ class ACL_CPP_API query
 	 * 设置单精度浮点类型的变量值
 	 * @param name {const char*} 变量名
 	 * @param value {float} 单精度浮点类型
+	 * @param precision {int} 尾数的精度值
 	 * @return {query&}
 	 */
-	query& set_parameter(const char* name, float value);
+	query& set_parameter(const char* name, float value, int precision = 8);
 
 	/**
 	 * 设置双精度浮点类型的变量值
 	 * @param name {const char*} 变量名
 	 * @param value {double} 双精度浮点类型
+	 * @param precision {int} 尾数的精度值
 	 * @return {query&}
 	 */
-	query& set_parameter(const char* name, double value);
+	query& set_parameter(const char* name, double value, int precision = 8);
 
 	/**
 	 * 设置 64 位短整类型的变量值
@@ -161,6 +163,7 @@ class ACL_CPP_API query
 	{
 		char type;
 		int  dlen;
+		int  precision;
 		union
 		{
 			char  c;

lib_acl_cpp/samples/db/query/main.cpp

@@ -26,9 +26,10 @@ int main(void)
 
 	int age = 20;
 	query.create_sql("update table set name=:name, age=%d"
-		", home=:home where nick=:name", age)
+		", home=:home where nick=:name and price=:price", age)
 		.set_parameter("name", "zsx1&xsz1")
-		.set_parameter("home", "回龙观");
+		.set_parameter("home", "回龙观")
+		.set_parameter("price", 1.00212, 6);
 	printf("sql: %s\r\n", query.to_string().c_str());
 
 	query.reset();

lib_acl_cpp/src/db/query.cpp

@@ -1,6 +1,7 @@
 #include "acl_stdafx.hpp"
 #include <assert.h>
 #include "acl_cpp/stdlib/log.hpp"
+#include "acl_cpp/stdlib/snprintf.hpp"
 #include "acl_cpp/db/query.hpp"
 
 namespace acl
@@ -39,6 +40,8 @@ bool query::append_key(string& buf, char* key)
 		return false;
 	}
 
+	char fmt[256];
+
 	query_param* param = it->second;
 	switch (param->type)
 	{
@@ -58,6 +61,14 @@ bool query::append_key(string& buf, char* key)
 		buf.format_append("'%s'",
 			escape(param->v.S, param->dlen, buf_).c_str());
 		break;
+	case DB_PARAM_FLOAT:
+		safe_snprintf(fmt, sizeof(fmt), "%%.%df", param->precision);
+		buf.format_append(fmt, param->v.f);
+		break;
+	case DB_PARAM_DOUBLE:
+		safe_snprintf(fmt, sizeof(fmt), "%%.%df", param->precision);
+		buf.format_append(fmt, param->v.d);
+		break;
 	default:
 		logger_error("unknown type: %d", param->type);
 		break;
@@ -210,7 +221,7 @@ query& query::set_parameter(const char* name, acl_int64 value)
 	return *this;
 }
 
-query& query::set_parameter(const char* name, float value)
+query& query::set_parameter(const char* name, float value, int precision /* = 8 */)
 {
 	string key(name);
 	key.lower();
@@ -220,12 +231,16 @@ query& query::set_parameter(const char* name, float value)
 	param->type = DB_PARAM_FLOAT;
 	param->v.f = value;
 	param->dlen = sizeof(float);
+	if (precision >= 0)
+		param->precision = precision;
+	else
+		param->precision = 8;
 
 	params_[key] = param;
 	return *this;
 }
 
-query& query::set_parameter(const char* name, double value)
+query& query::set_parameter(const char* name, double value, int precision /* = 8 */)
 {
 	string key(name);
 	key.lower();
@@ -235,6 +250,10 @@ query& query::set_parameter(const char* name, double value)
 	param->type = DB_PARAM_DOUBLE;
 	param->v.d = value;
 	param->dlen = sizeof(double);
+	if (precision >= 0)
+		param->precision = precision;
+	else
+		param->precision = 8;
 
 	params_[key] = param;
 	return *this;