r-PostgresqlR/DBI表示表不存在

Question

我正在使用R 3.6.3和PostgreSQL 12。我在数据库中有几个表。其中一个有8000000多行，我正试图将其发送到R。我使用的是依赖于DBI的RPostgreSQL包。

> library(RPostgreSQL)
Loading required package: DBI
Warning message:
package ‘RPostgreSQL’ was built under R version 3.6.2 
> drv <- dbDriver("PostgreSQL")
> con <- dbConnect(drv, dbname="ebird_work",host="localhost", port=5432, user="postgres")
> dbListTables(con)
[1] "spatial_ref_sys" "grid_sampl"      "gridpt_of_buf"   "or_counties"    
[5] "e_grid"          "ebird_sel_spt"   "ebird_or_cov"    "ebird_dct"      
[9] "ebird_sim"       "fin_pt_no"       "eb_new"          "samp_pt"        
[13] "or_buffered"  

我正试着拉上ebird_sel_spt。但是

> dbExistsTable(con, "ebird_sel_spt")
[1] FALSE

因此，以下查询不起作用。

> dbSendQuery(con, "SELECT * FROM ebird_sel_spt LIMIT 1")
Error in postgresqlExecStatement(conn, statement, ...) : 
RS-DBI driver: (could not Retrieve the result : ERROR:  relation "ebird_sel_spt" does not exist
LINE 1: SELECT * FROM ebird_sel_spt LIMIT 1
^
)

来自PostgreSQL：

SELECT
*
FROM
pg_catalog.pg_tables
WHERE
schemaname != 'pg_catalog'
AND schemaname != 'information_schema';
"p_loc" "ebird_sel_spt" "postgres"      false   false   false   false

我是PostgreSQL的新手，并与R一起使用它。我做错了什么？

编辑-在@Parfait的回答之后：我尝试将"p_loc"与一起使用。连接器，但我仍然会遇到错误。我更新了R和RPostgreSQL，因为一开始有警告说它是在旧版本下构建的。错误仍然存在。我还应该找什么？

> library(RPostgreSQL)
Loading required package: DBI
> drv <- dbDriver("PostgreSQL")
> con <- dbConnect(drv, dbname="ebird_work",host="localhost", port=5432, user="postgres")
> dbListTables(con)
[1] "spatial_ref_sys" "grid_sampl"      "gridpt_of_buf"   "or_counties"    
[5] "e_grid"          "ebird_sel_spt"   "ebird_or_cov"    "ebird_dct"      
[9] "ebird_sim"       "fin_pt_no"       "eb_new"          "samp_pt"        
[13] "or_buffered"    
> dbExistsTable(con, "ebird_sel_spt")
[1] FALSE
> dbExistsTable(con, "p_loc.ebird_sel_spt")
[1] FALSE
> t <- Id(schema = "p_loc", table = "ebird_sel_spt")
> dbExistsTable(con, t)
[1] FALSE
> con
<PostgreSQLConnection>
> sessionInfo()
R version 3.6.3 (2020-02-29)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 17763)
Matrix products: default
locale:
[1] LC_COLLATE=English_United States.1252 
[2] LC_CTYPE=English_United States.1252   
[3] LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    
attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     
other attached packages:
[1] RPostgreSQL_0.6-2 DBI_1.1.0        
loaded via a namespace (and not attached):
[1] compiler_3.6.3

根据@Parfait:的请求进行编辑

#tried a different table to see if the problem was unique to my
#to the table I was interested in. it's not.
> dbExistsTable(con, "p_loc.or_counties")
[1] FALSE
> dbSendQuery(con, "SELECT * FROM p_loc.ebird_sel_spt LIMIT 1")
<PostgreSQLResult>
Warning message:
In postgresqlExecStatement(conn, statement, ...) :
RS-DBI driver warning: (unrecognized PostgreSQL field type geometry (id:29533) in column 18)

我再次进行了pgtable查询：

schemename tablename         tableowner tablespace hasindexes hasrules hastriggers rowsecurity
"public"   "spatial_ref_sys" "postgres" [NULL]     true        false      false       false
"p_loc"    "or_counties"     "postgres" [NULL]     true        false  false       false
"p_loc"    "e_grid"          "postgres" [NULL]     true        false  false       false
"p_loc"    "ebird_sel_spt"   "postgres" [NULL]     false       false  false       false

第二版这是在@Parfait对他的答案进行编辑之后发布的。答案似乎是有效的，我会马上记下来。

> dbExistsTable(con, c("p_loc", "ebird_sel_spt"))
[1] TRUE
> df <- dbGetQuery(con, "SELECT * FROM p_loc.ebird_sel_spt LIMIT 1")
Warning message:
In postgresqlExecStatement(conn, statement, ...) :
RS-DBI driver warning: (unrecognized PostgreSQL field type geometry (id:29533) in column 18)
> df
GLOBAL_UNIQUE_IDENTIFIER                         COMMON_NAME
URN:CornellLabOfOrnithology:EBIRD:OBS543103161 Band-tailed Pigeon
SCIENTIFIC_NAME         OBSERVATION_COUNT STATE_PROVINCE     COUNTY LOCALITY
Patagioenas fasciata                  1 Oregon             Washington   CRNA 5
LONGITUDE LATITUDE OBSERVATION_DATE TIME_OBSERVATIONS_STARTED
-123.0843  45.4498       2012-06-03                  06:22:00
FIRST_NAME                              LAST_NAME PROTOCOL_TYPE
Metro Parks and Nature Avian Monitoring      Weil    Stationary
ALL_SPECIES_REPORTED SAMPLING_EVENT_IDENTIFIER            OBS_TIME  point
1                 S40033350 2012-06-03 06:22:00 120747
geom   pt_lon  pt_lat
01010000201E690000F851624162191E41A6F66655B8325341 493144.6 5032673

Answer 1

当您的pg_catalog.pg_tables查询显示哪些表省略了重要的列标题时，该表存在于非默认模式(即非public模式(中，特别是在p_loc:中

| schemaname | tablename     | tableowner | tablespace | hasindexes | hasrule | hastriggers |
|------------|---------------|------------|------------|------------|---------|-------------|
| p_loc      | ebird_sel_spt | postgres   | NULL       | false      | false   | false       |

因此，考虑在所需的方法调用中识别模式，或者在SQL中使用句点限定符，如下模式：database.schema.table.column:

# SCHEMA NAMESPACE
dbExistsTable(con, c("p_loc", "ebird_sel_spt"))
df <- dbReadTable(con, c("p_loc", "ebird_sel_spt"))
# SQL PERIOD-QUALIFIER
df <- dbGetQuery(con, "SELECT * FROM p_loc.ebird_sel_spt LIMIT 1")