浮点数 mysql golang 时间序列 32位浮点 64位浮点 float32 float64 保证一定有一行返回
3)
保证一定有一行返回
SELECT COUNT(*),IF(a.Id IS NULL,0,123) ,a.Id
2)
mysql
`ThresholdMin` DECIMAL(20,6) NOT NULL DEFAULT '0.000000' COMMENT '阈值下限',
`ThresholdMax` DECIMAL(20,6) NOT NULL DEFAULT '0.000000' COMMENT '阈值上限',
-4294967296.000000
4294967295.000000
取出后
float32
Max: 4294967300
Min: -4294967300
float64
cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 79
model name : Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz
stepping : 1
microcode : 0xb00002e
cpu MHz : 2097.570
cache size : 20480 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 20
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch invpcid_single ssbd ibrs ibpb stibp kaiser fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 invpcid rtm rdseed adx smap xsaveopt arat flush_l1d arch_capabilities
bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs taa itlb_multihit
bogomips : 4195.14
clflush size : 64
cache_alignment : 64
address sizes : 43 bits physical, 48 bits virtual
power management:
1)
1.6607259e+09 1660725877
for rows.Next() { var X float32 var Y string var a int32 err = rows.Scan(&Y, &X, &a)
1660725945
1660725952