# Issues with converting from ODBC.API.SQLDate to Date - can't do any operations on SQLDate
**URL:** https://discourse.julialang.org/t/issues-with-converting-from-odbc-api-sqldate-to-date-cant-do-any-operations-on-sqldate/9340
**Category:** New to Julia
**Tags:** dates
**Created:** [February 26, 2018, 1:57pm UTC](https://discourse.julialang.org/t/issues-with-converting-from-odbc-api-sqldate-to-date-cant-do-any-operations-on-sqldate/9340 "2018-02-26T13:57:45Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Max-Zara](https://discourse.julialang.org/u/Max-Zara)
#### Post date: [February 26, 2018, 1:57pm UTC](https://discourse.julialang.org/t/issues-with-converting-from-odbc-api-sqldate-to-date-cant-do-any-operations-on-sqldate/9340/1 "2018-02-26T13:57:45Z")
Hi,
I have a query which gives me a list of dates from PostgreSQL via ODBC. The array looks like this:
head(tmp\_df)
6×11 DataFrames.DataFrame
│ Row │ Date │ 8748 │ 8903 │ 9668 │ 9671 │ 9690 │ 10016 │ 10790 │ 11146 │ 11150 │ 11151 │
├─────┼────────────┼──────┼──────┼───────┼───────┼──────┼───────┼───────┼───────┼───────┼───────┤
│ 1 │ 2006-01-31 │ 2.07 │ 0.0 │ 1.92 │ 2.05 │ 0.0 │ 3.7 │ 0.0 │ 6.24 │ 6.23 │ 2.88 │
│ 2 │ 2006-02-28 │ 1.21 │ 0.0 │ 1.63 │ -0.55 │ 0.0 │ 0.56 │ 0.0 │ 3.53 │ 3.55 │ 0.14 │
│ 3 │ 2006-03-31 │ 1.96 │ 0.0 │ 1.18 │ 1.72 │ 0.0 │ 0.57 │ 0.0 │ -0.82 │ -0.85 │ 2.15 │
│ 4 │ 2006-04-30 │ 0.85 │ 0.0 │ -0.02 │ 0.75 │ 0.0 │ -0.86 │ 0.0 │ 0.61 │ 0.57 │ 2.32 │
│ 5 │ 2006-05-31 │ 0.69 │ 0.0 │ 3.66 │ 2.91 │ 0.0 │ 0.66 │ 0.0 │ -7.74 │ -8.11 │ -1.71 │
│ 6 │ 2006-06-30 │ 0.05 │ 0.0 │ 0.29 │ 0.57 │ 0.0 │ -0.44 │ 0.0 │ 6.21 │ 6.2 │ 1.94 │
the typeof(tmp\_df[:Date]) is DataArrays.DataArray{ODBC.API.SQLDate,1}
I can’t seem to convert it to Date format to do any operations on:
convert(Date,tmp\_df[:Date])
ERROR: MethodError: Cannot `convert` an object of type DataArrays.DataArray{ODBC.API.SQLDate,1} to a
n object of type Date
This may have arisen from a call to the constructor Date(…),
since type constructors fall back to convert methods
tmp\_df[:Date]+Dates.Day(1)
ERROR: MethodError: no method matching +(::DataArrays.DataArray{ODBC.API.SQLDate,1}, ::Base.Dates.Da
y)
How can this be fixed? Thank you in advance
---
### Author:  [@Liso](https://discourse.julialang.org/u/Liso)
#### Post date: [February 26, 2018, 2:36pm UTC](https://discourse.julialang.org/t/issues-with-converting-from-odbc-api-sqldate-to-date-cant-do-any-operations-on-sqldate/9340/2 "2018-02-26T14:36:13Z")
I don’t know if it is best way, but you could try this:
```julia
Julia> import ODBC
Julia> arr = [ODBC.API.SQLDate(2018, 2,i) for i in 1:3] # create example array
3-element Array{ODBC.API.SQLDate,1}:
2018-02-01
2018-02-02
2018-02-03
julia> [Date(i.year, i.month, i.day) for i in arr] # new array with Date type elements
3-element Array{Date,1}:
2018-02-01
2018-02-02
2018-02-03
```
---
### Author:  [@nalimilan](https://discourse.julialang.org/u/nalimilan)
#### Post date: [February 26, 2018, 9:33pm UTC](https://discourse.julialang.org/t/issues-with-converting-from-odbc-api-sqldate-to-date-cant-do-any-operations-on-sqldate/9340/3 "2018-02-26T21:33:31Z")
`mp_df[:Date]` refers to a column of the data frame, which is an array object. You cannot convert it to a `Date`, but possibly to an `Array{Date}`, for example using `convert(Array{Date}, mp_df[:Date])`, `Date.(mp_df[:Date])` (untested), or the more explicit form @Liso proposed.
---
### Author:  [@js135005](https://discourse.julialang.org/u/js135005)
#### Post date: [February 26, 2018, 9:47pm UTC](https://discourse.julialang.org/t/issues-with-converting-from-odbc-api-sqldate-to-date-cant-do-any-operations-on-sqldate/9340/4 "2018-02-26T21:47:57Z")
I ran into the same issue and ended up creating a function to handle the problem.
```julia
function odttodt(odt::Union{Missings.Missing, ODBC.API.SQLTimestamp})::Union{Missings.Missing, DateTime}
ismissing(odt) && return odt
return DateTime(odt.year, odt.month, odt.day, odt.hour, odt.minute, odt.second, (odt.fraction / 1000000))
end # odttodt
ctrdf[:RunDT] = missings(DateTime, size(ctrdf, 1))
ctrdf[:RunDT] .= odttodt.(ctrdf[:tRunDT])
```
As you can see above, I could then use the dot syntax to convert an entire dataframe column. Note that I use datetime format and had to handle the difference between milliseconds, microseconds, and nanoseconds in the different formats.
A simpler variant of this would handle going to Date format for your use case.