github.com/qxnw/lib4go@v0.0.0-20180426074627-c80c7e84b925/db/tpl/tpl.analyze.go (about)

     1  package tpl
     2  
     3  import (
     4  	"fmt"
     5  	"regexp"
     6  )
     7  
     8  func isNil(input interface{}) bool {
     9  	return input == nil || fmt.Sprintf("%v", input) == ""
    10  }
    11  
    12  type tplCache struct {
    13  	sql    string
    14  	params []interface{}
    15  	names  []string
    16  }
    17  
    18  //AnalyzeTPLFromCache 从缓存中获取已解析的SQL语句
    19  func AnalyzeTPLFromCache(name string, tpl string, input map[string]interface{}, prefix func() string) (sql string, params []interface{}) {
    20  	sql, params, _ = AnalyzeTPL(tpl, input, prefix)
    21  	return
    22  	/*key := fmt.Sprintf("%s_%s", name, tpl)
    23  	b, cache, _ := tplCaches.SetIfAbsentCb(key, func(i ...interface{}) (interface{}, error) {
    24  		sql, params, names := AnalyzeTPL(tpl, input, prefix)
    25  		return &tplCache{sql: sql, params: params, names: names}, nil
    26  	})
    27  	value := cache.(*tplCache)
    28  	if b {
    29  		return value.sql, value.params
    30  	}
    31  	params = make([]interface{}, 0, len(value.names))
    32  	for _, v := range value.names {
    33  		va := input[v]
    34  		if !isNil(va) {
    35  			params = append(params, va)
    36  		} else {
    37  			params = append(params, nil)
    38  		}
    39  	}
    40  	return value.sql, params*/
    41  }
    42  
    43  //AnalyzeTPL 解析模板内容，并返回解析后的SQL语句，入输入参数
    44  //@表达式，替换为参数化字符如: :1,:2,:3
    45  //#表达式，替换为指定值，值为空时返回NULL
    46  //~表达式，检查值，值为空时返加"",否则返回: , name=value
    47  //&条件表达式，检查值，值为空时返加"",否则返回: and name=value
    48  //|条件表达式，检查值，值为空时返回"", 否则返回: or name=value
    49  func AnalyzeTPL(tpl string, input map[string]interface{}, prefix func() string) (sql string, params []interface{}, names []string) {
    50  	params = make([]interface{}, 0)
    51  	names = make([]string, 0)
    52  	word, _ := regexp.Compile(`[@|#|&|~|\||!]\w+`)
    53  	//@变量, 将数据放入params中
    54  	sql = word.ReplaceAllStringFunc(tpl, func(s string) string {
    55  		//fullKey := s[1:]
    56  		key := s[1:]
    57  		//if strings.Index(fullKey, ".") > 0 {
    58  		//key = strings.Split(fullKey, ".")[1]
    59  		//}
    60  		pre := s[:1]
    61  		value := input[key]
    62  		switch pre {
    63  		case "@":
    64  			if !isNil(value) {
    65  				names = append(names, key)
    66  				params = append(params, value)
    67  			} else {
    68  				names = append(names, key)
    69  				params = append(params, nil)
    70  			}
    71  
    72  			return prefix()
    73  		case "#":
    74  			if !isNil(value) {
    75  				return fmt.Sprintf("%v", value)
    76  			}
    77  			return "NULL"
    78  		case "&":
    79  			if !isNil(value) {
    80  				names = append(names, key)
    81  				params = append(params, value)
    82  				return fmt.Sprintf("and %s=%s", key, prefix())
    83  			}
    84  			return ""
    85  		case "|":
    86  			if !isNil(value) {
    87  				names = append(names, key)
    88  				params = append(params, value)
    89  				return fmt.Sprintf("or %s=%s", key, prefix())
    90  			}
    91  			return ""
    92  		case "~":
    93  			if !isNil(value) {
    94  				names = append(names, key)
    95  				params = append(params, value)
    96  				return fmt.Sprintf(",%s=%s", key, prefix())
    97  			}
    98  			return ""
    99  		default:
   100  			return s
   101  		}
   102  	})
   103  	return
   104  }