回答編集履歴
2
ユーザー変数
test
CHANGED
@@ -75,3 +75,21 @@
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75
75
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```
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76
76
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77
77
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78
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+
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79
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+
MySQL ならユーザー変数でもできるでしょうか。
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80
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+
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81
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+
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82
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+
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83
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+
```sql
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84
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+
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85
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set @new_id:=null;
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86
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+
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87
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+
select id, flags, if(flags=2, @new_id:=id, @new_id) as new_id
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88
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+
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89
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from t
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90
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+
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91
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order by id
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92
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+
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93
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```
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94
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+
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95
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+
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1
サブクエリを使わずに
test
CHANGED
@@ -2,7 +2,7 @@
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2
2
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3
3
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4
4
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5
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-
```
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5
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+
```sql
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6
6
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7
7
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select
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8
8
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@@ -55,3 +55,23 @@
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55
55
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+------+-------+--------+
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56
56
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57
57
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```
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58
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+
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59
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+
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60
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+
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61
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+
サブクエリを使わずにこんな感じでもできるでしょうか。
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62
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+
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63
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+
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64
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+
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65
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+
```sql
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66
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+
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67
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+
select t.id, t.flags, max(s.id) as new_id
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68
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+
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69
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from t join t as s
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70
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+
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71
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where s.id <= t.id and s.flags = 2
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72
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+
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73
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group by t.id, t.flags
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74
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+
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75
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+
```
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76
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+
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77
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+
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