Insert timestamp data into MySql database from R - r

Question

I want to insert data from an R dataframe into a MySql table.
Everything works fine except the column geburtstage which is of the type timestamp.
The class of the column geburtstage in the dataframe is "POSIXct" "POSIXt".
The result in the database is always 0000-00-00 00:00:00.
Here my R session:
library(XLConnect)
excel.file <- file.path("c:/path/test.xlsx")
elements <- readWorksheetFromFile(excel.file, sheet=1)
elements
name nummer geburtsdatum
1 Anton 1 1967-05-11
2 Berti 2 1964-05-14
3 Conni 3 1967-01-01
4 Det 4 1967-01-01
5 Edi 5 1967-01-01
6 Fritzchen 6 1967-01-01
class(elements$geburtsdatum)
[1] "POSIXct" "POSIXt"
library(RMySQL)
library(DBI)
con <- dbConnect(RMySQL::MySQL(), host = "127.0.0.1", user = "root", password = "xxxx", dbname = "test")
dbWriteTable(
+ conn = con,
+ name='testdaten3',
+ value = elements,
+ row.names = FALSE,
+ append = TRUE,
+ field.types = c(
+ name = "varchar(45)",
+ nummer = "tinyint",
+ geburtsdatum = 'timestamp'
+ )
+ )
[1] TRUE
--- end of R session ---
MySql database table testdaten3:
id name nummer geburtsdatum
1 Anton 1 0000-00-00 00:00:00
2 Berti 2 0000-00-00 00:00:00
3 Conni 3 0000-00-00 00:00:00
4 Det 4 0000-00-00 00:00:00
5 Edi 5 0000-00-00 00:00:00
6 Fritzchen 6 0000-00-00 00:00:00
I already tried to convert the data like that:
elements$geburtsdatum <- format(elements$geburtsdatum,'%Y-%m-%d %H:%M:%S')
But the result was the same.
I use RStudio Version 1.1.456 with R 3.5.1 under Windows 8.1 and a MySql Server 5.6.
Can anybody help?
Kind regards
Goetz Edinger

Answer 1

From your example, it seems like geburtsdatum is just a date, with no time value. In that case, why not use as.Date(elements$geburtsdatum) to change it to a date type in your data frame and then use CONCAT to add it to the MySQL db?
Like this:
CONCAT(elements$geburtsdatum, " ", "00:00:00")
Basically, you are adding the birthday to a placeholder time value in order to make a timestamp.

Answer 2

Thank You!!
I found the mistake. If I use a date before '1970-01-01 01:00:01' the date is changed by the database to '0000-00-00 00:00:00'. So if I use a date which is equal to '1970-01-01 01:00:01' or newer the result is correct. It doesn't matter if I do it over R or over MySQL workbench.
* PROBLEM SOLVED *