join

问题 This query returns all the elements in the table la and all nulls for fields coming from the lar table which is not what I expected. SELECT la.listing_id, la.id, lar.* FROM la LEFT JOIN lar ON lar.application_id = la.id AND la.listing_id = 2780; This query returns correct and expected results but shouldn't both queries do the same thing ? SELECT la.listing_id, la.id, lar.* FROM la LEFT JOIN lar ON lar.application_id = la.id WHERE la.listing_id = 2780; What am I missing here? I want to make

问题 This query returns all the elements in the table la and all nulls for fields coming from the lar table which is not what I expected. SELECT la.listing_id, la.id, lar.* FROM la LEFT JOIN lar ON lar.application_id = la.id AND la.listing_id = 2780; This query returns correct and expected results but shouldn't both queries do the same thing ? SELECT la.listing_id, la.id, lar.* FROM la LEFT JOIN lar ON lar.application_id = la.id WHERE la.listing_id = 2780; What am I missing here? I want to make

问题 I want to join 3 tables which Table A have date and time in different field that need to be combined first so it can be compared on Table B using field timestamp. Table A userid | date_in | check_in --------+------------+---------- 145 | 2017-01-23 | 08:56:05 254 | 2017-01-24 | 08:56:54 202 | 2017-01-25 | 08:53:26 15 | 2017-01-26 | 08:47:40 Table B userid | checktime | sn --------+---------------------+--------------- 145 | 2017-01-23 08:56:05 | 0345135200184 254 | 2017-01-24 08:56:54 |

问题 I want to join 3 tables which Table A have date and time in different field that need to be combined first so it can be compared on Table B using field timestamp. Table A userid | date_in | check_in --------+------------+---------- 145 | 2017-01-23 | 08:56:05 254 | 2017-01-24 | 08:56:54 202 | 2017-01-25 | 08:53:26 15 | 2017-01-26 | 08:47:40 Table B userid | checktime | sn --------+---------------------+--------------- 145 | 2017-01-23 08:56:05 | 0345135200184 254 | 2017-01-24 08:56:54 |

问题 I am trying to translate the query below to criteria api. SELECT er from ereturn er JOIN FETCH product_item pi ON pi.ereturn_id = er.id WHERE pi.status = "RECEIVED" To something like this: CriteriaBuilder builder = em.getCriteriaBuilder(); CriteriaQuery<Ereturn> criteria = builder.createQuery( Ereturn.class ); Root<Ereturn> er = criteria.from(Ereturn.class); Join<Ereturn, ProductItem> productItemJoin = er.join("productItems", JoinType.LEFT); Fetch<Ereturn, ProductItem> productItemFetch = er

问题 I am trying to translate the query below to criteria api. SELECT er from ereturn er JOIN FETCH product_item pi ON pi.ereturn_id = er.id WHERE pi.status = "RECEIVED" To something like this: CriteriaBuilder builder = em.getCriteriaBuilder(); CriteriaQuery<Ereturn> criteria = builder.createQuery( Ereturn.class ); Root<Ereturn> er = criteria.from(Ereturn.class); Join<Ereturn, ProductItem> productItemJoin = er.join("productItems", JoinType.LEFT); Fetch<Ereturn, ProductItem> productItemFetch = er

问题 Consider the following single index DataFrame: energy fat 1 2000 28 2 1900 17 3 2200 30 4 1750 15 5 1800 18 6 1600 12 I also have a multindex Series: 1 vitamin-c 0.0004 vitamin-a 0.0150 2 vitamin-c 0.0030 3 vitamin-d 1.2000 vitamin-e 1.0007 vitamin-c 1.2020 4 vitamin-a 0.0780 5 vitamin-b 0.9650 6 vitamin-e 1.9801 vitamin-c 1.0011 How can I join the two so the result looks like this: energy fat vitamins 1 2000 28 vitamin-c 0.0004 vitamin-a 0.0150 2 1900 17 vitamin-c 0.0030 3 2200 30 vitamin-d

问题 Consider the following single index DataFrame: energy fat 1 2000 28 2 1900 17 3 2200 30 4 1750 15 5 1800 18 6 1600 12 I also have a multindex Series: 1 vitamin-c 0.0004 vitamin-a 0.0150 2 vitamin-c 0.0030 3 vitamin-d 1.2000 vitamin-e 1.0007 vitamin-c 1.2020 4 vitamin-a 0.0780 5 vitamin-b 0.9650 6 vitamin-e 1.9801 vitamin-c 1.0011 How can I join the two so the result looks like this: energy fat vitamins 1 2000 28 vitamin-c 0.0004 vitamin-a 0.0150 2 1900 17 vitamin-c 0.0030 3 2200 30 vitamin-d

问题 Consider the following single index DataFrame: energy fat 1 2000 28 2 1900 17 3 2200 30 4 1750 15 5 1800 18 6 1600 12 I also have a multindex Series: 1 vitamin-c 0.0004 vitamin-a 0.0150 2 vitamin-c 0.0030 3 vitamin-d 1.2000 vitamin-e 1.0007 vitamin-c 1.2020 4 vitamin-a 0.0780 5 vitamin-b 0.9650 6 vitamin-e 1.9801 vitamin-c 1.0011 How can I join the two so the result looks like this: energy fat vitamins 1 2000 28 vitamin-c 0.0004 vitamin-a 0.0150 2 1900 17 vitamin-c 0.0030 3 2200 30 vitamin-d

问题 Consider the following single index DataFrame: energy fat 1 2000 28 2 1900 17 3 2200 30 4 1750 15 5 1800 18 6 1600 12 I also have a multindex Series: 1 vitamin-c 0.0004 vitamin-a 0.0150 2 vitamin-c 0.0030 3 vitamin-d 1.2000 vitamin-e 1.0007 vitamin-c 1.2020 4 vitamin-a 0.0780 5 vitamin-b 0.9650 6 vitamin-e 1.9801 vitamin-c 1.0011 How can I join the two so the result looks like this: energy fat vitamins 1 2000 28 vitamin-c 0.0004 vitamin-a 0.0150 2 1900 17 vitamin-c 0.0030 3 2200 30 vitamin-d